Es Lab Final

7/31/2019 Es Lab Final

1/27

PROJECT 1

Aim:- Troubleshooting of Car.

Flowchart of Brake Failure


2/27

STEPS FOR BRAKE FAILURE OF CAR FLOWCHART:

1. Do the brakes fail to stop the car? If you have to step on the brake pedal harder than you want to inorder for the brakes to operate normally, the brakes do stop the car. What we're interested in here iswhen you have to push on the pedal with both feet and the car slowly rolls to a stop rather than locking

up the wheels, or when the pedal goes to the floor, won't pump up, and you have to yank theemergency brake or turn the engine off in gear in order to slow it down.

2. Does the brake pedal go to the floor? The absolute first thing to check when you still have pedal butthe car won't stop is that something really dumb isn't going on, like you took your shoes off to driveand they are jammed under the brake pedal But assuming nobody would need to go on the Internet tofigure that out, there is always the possibility that the pedal linkage is bind up under the dashboard, somake sure the brake pedal is really going through its full travel and not hanging up 3/4 of the waydown. Other problems that can lead to minimal braking are glazed brake parts, frozen pistons in thecalipers (though the steering should pull in only one caliper is frozen), brake lines that are pinched orobstructed, or a problem with in the master cylinder or power booster unit. If you're fond of hitting thebrakes when the car isn't running, you may exhaust the vacuum to the power booster and have the

brake pedal go lower and lower until you start the car. A bad seal in the master cylinder can leave thepedal with some feel of resistance but fail to apply enough pressure to the caliper or wheel cylinderpistons to stop the car.

3. Is the brake fluid level OK? If there isn't enough brake fluid in the master cylinder to resist the piston,the pedal will go to the floor and the brakes won't function. The only "good" reason to be short brakefluid is if you just did a brake job didn't tighten a bleeder screw enough or somehow forgot to make upthe fluid you lost after bleeding the brakes, which you might blame on your pedal pushing assistant.Make up the brake fluid in both reservoirs of the master cylinder to the fill line, and poke the rubberseal on the lid back into shape so the reservoir doesn't overflow as soon as you put it back on. Bleedthe brakes following the order given by the manual, and make up the level after each wheel. Yourbrake fluid level does fall normally with the years as your disc pads and rotors wear down, leaving the

caliper pistons further and further extended in the cylinder. If you have rear brake shoes and drums,their wearing will make the pedal softer and softer, but the return springs may keep the reservoir levelup.

4. But the usual reason for the fluid level to drop through the bottom, especially in cases of outright brakefailure, is a leak in the hydraulic system. Start is inspecting the wheels and tires on the ground to see ifthere's obvious brake fluid leaking out. Check around the master cylinder is for a leak, and make surethe master cylinder lid was secured, or it will simply overflow when the brakes are applied. Before youmove the car, check carefully for the location of any suspicious fluid spots on the ground, because ifthe failure is a pinhole leak in a rusted steel brake line, it may be difficult to locate later withoutrefilling the master cylinder and having somebody hit the brakes to squirt out brake fluid (normally inyour eye, if you're under the car looking).

5. Does a brake warning light come on the instrument panel? Check to make sure the parking brake isnt on, and then takes the time to find the mechanical switch for the parking brake and make sure it isn'tstuck. If the brake warning light is in fact an error condition being reported by the antilock brakingsystem (ABS) or power booster, you'll need the shop manual or a good aftermarket manual to find outif any information can be coaxed out of the idiot light by following some procedure. But in the casethat the brake pedal goes to the floor, the brake fluid in the master cylinder level is fine and the brakewarning light isn't complaining, you must have a problem in the master cylinder or power booster


3/27

Before you jump to the conclusion that there's a blown piston seal inside the master cylinder, read up onthe power assist unit, and see if the pedal to the floor behavior can be caused by a vacuum failure or otherbooster problem.

6. Is this a parking emergency brake failure? When you pull the emergency brake lever between the seats(or under the dashboard) or push down the parking brake pedal, it should stiffen up quickly and ratchet

audibly, whether or not it provides much braking force. If the parking brake won't hold the car fromrolling backwards on a hill in neutral, it's not working properly. Some heavier vehicles with all discbrakes are notorious for having crummy parking brakes kludged onto the disc systems, but if theydon't hold the car from going forward from a dead stop in gear, good luck passing inspection.

7. Is a rear wheel locked? Sometimes the emergency brake works too good, which is to say, it locks up arear wheel and doesn't let it go. This is more likely to happen when a car sits for a while and the returnsprings take a set or the cable rusts up in the its sheath. Drive forward a couple feet so you can see

which wheel is locked (it will leave a drag mark), then shut down, get out of the car and try bouncingthat corner of the car up and down vigorously. If you hear a snap or a clunk and the brake releases, thatwas probably the cable letting go from its bound or slightly rusted state. Spraying some penetrating oilup into the metal sheath of the cable may help prevent it from happening again for a while, just don't

get any inside the brake drum of on the pads. If that doesn't work, flexing the cable sheaths (withinreason, you can't crimp them) and further applying and releasing the brake may help. You can oftendrive off a locked parking brake, but if it doesn't free up within a couple hundred yards, your riskingoverheating and causing real damage. If it happens once after leaving a car for the winter, it's no bigdeal, but if it happens every time you use the parking brake, it's time to replace the cables and springs.

8. Does the parking brake lever or pedal ratchet or move without force? If the parking brake movesthrough its range without any force, whether it makes the ratcheting noise or not, it's usually a cableproblem. The cable may be badly stretched or broken, the adjuster may have broken, or the spreader orequalizer that sends cable to both back wheels may have pulled off the undercarriage. You shouldn'ttry to repair a broken cable, just get a replacement and install it. The only trick is locating the brake, sowhich cable you need. Some systems run a single cable all the way from the emergency brake to onewheel, and attach a second cable to the spreader at the back of the car. Other systems use three cables,one from the parking brake back to the spreader, and one from each side of the spreader to each backwheel.

9. If the parking brake seems to operate normally in terms of the amount of force to apply it but doesn'tlock the wheels, it's possible that the cable is badly constricted in the protective sheath by corrosion,but it's more likely that the brakes are simply worn. If you have drums on the back, check the shoes forwear and check for any fluid leaks or glazing. Four wheel disc brakes accomplish the emergency brakefunction in two basic ways. The elegant solution is a more complicated caliper that includes amechanical linkage, such as a cam or threading that can be used to force out the piston and close thepads on the rotor by pulling on the cable. If you have discs with mini drums on the backs, they shouldbe good for the life of the car unless you accidentally drive a distance with the emergency brake onand glaze the parts.

10.Does one or more wheels drag too much? If you notice that your car can't roll forward from a full stopin neutral on gentle inclines, or even slows down and stops, your brakes are dragging too much. Putthe car up on jack stands and spin each wheel to see if they are all about the same or if one wheel

stands out as dragging to the point of being hard to spin, not even turning a full revolution withoutstopping when you give it a strong tug. If the problem is with a back wheel, a dragging parking brakeis the first suspect. Make sure that it's off, that it's the cables to the back wheels aren't taut, and back


4/27

off on the adjuster to loosen up the cable to the spreader if they are. Drum brakes generally dragbecause they are over-adjusted. Removing the drum when the brakes are over-adjusted is a drag in andof itself, you need to remove the little rubber access plug on the back of the wheel plate, push the autoadjuster out of the way, and back off the adjuster gear by hand with a screwdriver or brake spoon.

11.For disc brakes, the main suspect is a stuck piston, either one that is mechanically binding in thecylinder, or that is under continual hydraulic pressure. Try loosening the bleeder screw for that wheeland see if the piston backs off. If it does, you had (have) a problem with the hydraulic system,probably at the master cylinder or some balancing valve. If the wheel drags in jerky fashion, movingeasily and then locking, you probably have a warped rotor or some other rotor deformity. On rear discbrakes with the parking brake function built into the caliper, they may be adjusted too tight, but I'venever had to deal with it myself.

12.Do you need to pump up brake pedal? If the pedal is soft and you need to pump it and release it severaltimes before it firms up, it's usually a sign of air bubbles in the brake lines. The real question is whythere's air in the brake lines, whether there's a slow leak somewhere, a loose bleeder screw, a leakingseal on the master cylinder. If the problem creeps up on you very slowly and you never checked themaster cylinder, it's possible that the brake fluid level has been falling slowly as the parts wear, and the

lid seal isn't perfect. If it's not strictly a post-turning issue, skip down two paragraphs for bleeding.13.Does the problem only happen after turning? If you only have to pump up the brakes after turning, it'sa pretty good sign that something is forcing the piston back into the caliper as the front wheels turn.This means something is forcing the pads of their rest position, barely dragging on the rotor or disc.The most likely culprit is a warped rotor, but anything that causes the rotor to wobble is also suspect.If the rotor was ever removed, it's probably held in place my the wheel lugs at this point, so it could bea sign one or more lugs is loose, especially on a four bolt wheel where one missing lug can lead to

wobble..14.The fix for air in the brake lines is to bleed the brakes, normally starting as far as possible from the

master cylinder (rear-passenger side on most vehicles), followed by driver-side rear, passenger frontand finally driver side front. Some vehicles may allow you to bleed right at the master cylinder instead.

Brake is bled with the help of an assistant who sits in the car and presses and holds the brake pedalwhen told. You crack the bleeder screw open while there's pressure on the brake pedal and close it

again before the brake pedal is let up, otherwise air would be sucked right back into the system.15.If you aren't stingy about brake fluid use and you keep topping off the master cylinder and replacing

the lid, you can do a good job bleeding the brakes without any extra hoses or syringes. The technicallycorrect way to do it is with a transparent tube fit over the end of the bleeder screw, so you can see theair bubbles coming out (and see when the stop). But even without the tube, you can usually tell what'sgoing on by whether there's a clean stream of brake fluid as you assistant steps on the brakes, or if itgurgles and spurts.

16.Are the brakes making noises? If you have noises coming from the wheels, it may be the brakes or itmay be something else. Squealing and screeching noises are usually the brakes, ticking, grinding and

clunking noises may be the brakes, may be noises from the wheel bearings, CV joints or suspension.Brake noises do not imply bad braking performance, and in some cases, they are intentional warningnoises caused by the brake pad manufacturers putting slits or a different material in the pads at acertain depth to worn of wear.

17.Do you hear clunks whenever the brakes are applied? Clunks are generally easy to diagnose becausethey are generated when something heavy moves enough of a distance to go "clunk". In the case ofbrakes, the only part that's like to make a clunking noise is a caliper that's moving too freely on the
http://www.ifitjams.com/ticking.htmhttp://www.ifitjams.com/ticking.htm


5/27

wheel assembly, and the only reason for this (unless the steel is worn away) would be a loose pin. It'scommon to secure an automotive caliper with a single pin that's threaded at the end and which sits in arubber sleeve. If the pin backs out so that the bottom of the caliper is just along for the ride, you'll get a naclunk as it rides up when you hit the brakes. Eventually, it will mess up either the caliper or the wheelassembly, so fix it immediately.

18.Do the brakes scrape or grind? You'll recognize the scraping sound if you hear it; grinding noises aremore in the ear of the beholder. The scraping noise may be intentional, like the squeals mentionedearlier to warn you the pads are nearing the end of their design life. But scrapes and grinds are moreoften caused by a broken pad, a grooved rotor or drum, or a foreign piece of metal or rust jammed inbetween the braking surfaces. Grinding noises may also be from wheel bearings or CV joints, and ifthey are, they need to be replaced, not greased.

19.Do you get rattles from the brakes when driving on rough pavement? Rattling noises are almost alwaysdue to disc brake pads with missing spring clips (anti-noise clips) that are intended to keep them fromrattling against the wheel assembly guides when the brake isn't applied. If the rattling noise goes awaywhen you apply the brakes, however lightly, you know that it's the pads rattling. If you can't find theslips or figure out how to install them (don't laugh, it's tricky on some calipers), you may be able to use

an after-market product, check your local parts store.20.If you're getting ticks or short chirps from the brakes as you drive, it's likely a high spot on the rotorsor drum, or warping. Heat can warp metal brake parts in the course of a few minutes, like applying thebrakes steadily down a long hill on the highway. While it probably won't get any worse under normaldriving conditions, it will wear out you pads faster, and the brakes may lock quicker or pulse when youjam them on.

21.Do the brakes pull the steering wheel? If you step on the brakes and the steering wheel pulls to oneside or the other, that's the front brakes pulling it. The problem is either too much braking on the sidethat's pulling or too little breaking on the opposite side. Since too little breaking is easier totroubleshoot than too much, follow the instructions for bleeding that side, and check the brake parts forexcessive wear compared to the pulling side. You should never replace the disc brake pads on one

front wheel and not the other, they should always be done at the same time even if one side appears tohave plenty of meat left. If bleeding doesn't do it, there may be a problem with the caliper pistongetting cocked in the cylinder, and if it's near the end of it's throw, replacing the pads on both sides, oreven replacing worn rotors, may force the piston back into a good section of cylinder where theextension is less and it may live happily for years. It's also possible that you have a crimped brake line,or a problem with the master cylinder.

22.It's a good time to note that torque steer is sometimes confused with pulling brakes, though it's reallythe opposite thing. Torque steer is cause when a front wheel drive differential powers sends powerunevenly to the front wheels when you are going straight and accelerating. So if the steering wheelpulls when your foot isn't on the brakes and only when accelerating, you want to check all the issuesthat can cause torque steer, like unbalanced axles (could have been bent by impact with somethingunder the car), stuff stuck to the axle, or any problem with the differential, like low transmission fluid,etc. And if the car pulls to one side ALL the time, whether or not you are accelerating or braking, itcould well be that one of your front calipers is seized or partially seized. I've had this happen withbreak line failure when the line fails on the inside. When you hit the brakes, the car briefly pulls to theside that's operating properly since it gets the fill hydraulic pressure, but the stuck soon catches up ashydraulic fluid gets past the blockage. When you release the brakes, the steering pulls to the blockedside because the blockage maintains pressure until the fluid can leak past the blockage. Since there's


6/27

no real pressure to push the fluid back from the caliper, other than imperfections in the rotor, thecaliper can remain very tight, and your brakes will soon overheat and likely start smoking and smelling onthat side.

23.Is breaking action jerky or pulsing? If you have anti-lock brakes and you step on the brakes hard, apulsing pedal may just be the brakes in anti-lock mode doing their job. If you have anti-lock brakesand you aren't stepping hard on th pedal, it could be a sign that the ABS computer or sensors have

gone haywire. Otherwise, it's normally a sign of abnormal brake wearing, rotor or drum warp. One

way to check if the back brake parts are involved is to pull on the emergency brake very slowly andsee if it results if you can feel pulsing in the handle, which would be due to a deformity in the rear

brakes.24.Is it hard braking and bring the car to a halt? If you have to exert a lot of pedal pressure to get the car

to stop, that's hard braking. It's normally due to normal brake pad wear or glazing, but as with mostbraking issues, it could also be a problem with the hydraulics, leaking seals in a piston cylinder in acaliper or wheel cylinder. Can easily be a master cylinder or power boost problem as well, but if youaren't getting any warning lights, it makes sense to replace worn parts first.

25.If you are getting a warning light for brakes, make sure the emergency brake isn't set. If the emergencyis released and you have a brake warning light with no apparent braking problems, it could be a sensorin an ABS system or an error condition reported by the power booster, but it could also be a failed

switch on the emergency brake.


7/27

PROJECT 2

Aim:- Car wont start.

Flowchart for Car Wont Start


8/27


9/27


10/27

regulator to test, just remember that the alternator can't generate any electricity to charge the battery if thvoltage regulator doesn't send it power to generate an electric field. The alternator shaft is alwaysspinning, but no power is generated in the outer windings (stator) unless the rotor winding is powered. Tmost common failure with alternators, beyond the wiring harness, is probably when one of therectification diodes fail. Without rectification, the alternator would be putting out AC that would

alternately charge and discharge the battery.7. Have you cleaned the battery terminals switch? I actually forgot this one first time I did the flowchartbecause it's second nature, the first thing you'd do if you don't own a volt meter. If all you get isclicking from the starter relay when you turn the key, or if the car barely cranks over, there's a goodchance that the battery terminals are oxidized or dirty, If the connectors on the posts (terminals) are atall loose, that's likely your problem, and you can often get enough juice to start the car simply bytwisting the connector until it's in a tighter position. But the real fix is to remove the connectors, cleanthe posts up with some sandpaper or Emory cloth, and do the same inside to the inside surface of theconnector. If the bolt inside an old fashioned lead connector is corroded and broken, it need to bereplace in the long run, but if you just need to get home, simply crushing the connector a little and thenforcing it on the post so it's tight is a decent patch. Check the ground also. Remove the bolt on the

battery ground (where the black battery cable ends up), clean it, and put it back in again. Check theengine to chassis ground strap while you're at it.8. Cars and trucks use a starter relay switch so that the heavy wire supplying high current to the starter

from the battery shouldn't need to be wired through the ignition switch. When you turn the key to"start", a magnetic solenoid in the starter relay switch plunges down and connects the positive outputof the battery to the power cable running to the starter. If the relay fails or any of the fusing in the

starter circuit before the relay fails (perhaps for good reason, like a short), the starter won't get anypower. While there's always a chance it will cause damage, I'm in the habit of bypassing the starterrelay with whatever is handy, to power up the starter. Less radically, you can bypass the ignitionswitch to power the solenoid to actuate the starter relay, if it is operational but not getting turned onwith the ignition switch. Since this either of these approaches are bypassing the neutral safety switchand any other safety features, make darn sure the car is in park or neutral if you try it, or you may justrun yourself over.

9. There's not much else to do other than remove the starter and check it outside of the car. Make sureyou remove the ground cable from the battery before going to remove the starter or you can end upwelding your tools if there's circuit problem. Check the starter terminals for corrosion, doesn't takemuch to keep electricity from flowing. When the starter is out of the car, you should be able to test iteasily with a set of jumper cables, the ground on the case and the hot to the main terminal. Should spinthe main motor and kick the pinion gear out.

10.Does the engine fire and try to catch, or does it just crank over endlessly without ever trying to start.You don't want to spend minutes cranking an engine that makes no attempt to fire up, there's simplysomething wrong, it's not just cold. If it tries to start initially, but then just runs and turns withoutcatching, it's most likely a fuel problem. Either it's flooded out or it's not getting any fuel. My oldOmni has a tendency to dry out (gas wise) when it's been driven for more than a half hour or so andthen sits overnight. Can't pump too much gas into that carburetor for starting, I think the bowlbasically dries out or has some internal leak, but it's been that way for twenty years and gets great gasmileage, so why fiddle with it? If the engine backfires, it often indicates a timing problem. If theengine catches fire, a timing problem and a fuel leak could be at fault, but your first priority should befinding an extinguisher.


11/27

11.Is a spark getting to the plugs? Some sick as just grab the boot of a plug and touch the engine block tosee if they get a 20,000 Volt jolt, but that's no longer my idea of fun. I usually pull a spark plug wire,stick a screwdriver into the metal clip that would actually sit on the spark plug when the wire isinstalled, and then hold the screwdriver by the plastic handle with the metal shaft a quarter inch or soaway from a good ground on the engine while having somebody crank it over. A good spark will be

bright and cracking, you'll hear it zap. I only check one wire, I suppose it's always possible that thedistributor contacts for some other wire have failed, but even if only a one or two of the spark plugsare getting spark, the engine should attempt to fire.

12.Is there a spark from coil secondary? If you aren't getting any spark at the plugs, or if the spark looksor sounds weak, the problem is likely that the coil isn't operating properly. It's also possible that yourspark plug wires are totally shot and the resistance is so high that it's eating the sparks, but that's notnormally something that happens overnight. Good spark plug wires can last a decade. But to get aspark out of the coil, you don't just have to hold the secondary output near ground with the screwdrivertrick, you also need to short the coil negative to ground (just touch and go) using an alligator clip andprobe setup, to complete the circuit. Remember that any type of transformer (and coils are a type ofstep-up transformer) requires a changing current in order to operate, and grounding the coil negative

intermittently is a hack way to get a current surge in the primary winding.13.Do you have a mechanical distributor? A mechanical distributor is easily identified by a rounddistributor cap with all the spark plug wires attached to towers spaced along the edge and the coilsecondary wire plugged into the tower in the middle. Underneath the cap, held on by two clips orscrews, is a rotor mounted on a shaft that is mechanically turned by by that shaft being geared into thecamshaft. So the distributor rotor position is married to the valve positions for the cylinders, and theexact spark timing is set by turning the distributor cap relative to the shaft and securing it with a hold -down to the engine. Depending on how old the car is, there will either be points, which draw the sparkby opening and closing the circuit when the distributor shaft lobe opens and closes the points, or a Halleffect pick-up, an electromagnetic pickup that feeds the distributor shaft position back to the sparkcontrol computer which has some say in advancing or retarding the spark.

14.You can clean the rotor contact, though the metal will slowly get corroded by the high voltage overtime, increasing the gap to the cap until it needs replacing. The contacts on the cap (or the spark plugwire ends where they come through the cap to provide the contacts) may be slowly eaten away by thehigh voltage over the years. If that's the case with the wires, simply turning them over so the other sideof the wire contact faces the rotor may extend their life a few years. The magnetic pick -ups do fail, theones on my Chrysler 2.2 went every few years, with the usual symptom being the occasional stall (onthe highway,) or very hard starting. You can test them in place if you find the shop manualinstructions, but it's more complicated than most people will want to fool with for a $25 part. For trueelectronic distributors, see the manual for diagnostics, and don't neglect to check if there are any OBDII codes present.

15.Reading 12V+ at coil primary? With the key on "run", you should see the battery voltage at thepositive input terminal of the coil for the primary winding. If it's not there, the coil can't make sparks,so you'll have to trace it back through the ignition circuit. The "run" circuit and the "start" circuit forcars share a good chunk of the components, but the "run" circuit obviously eliminates the starter. Iwouldn't suggest jumping direct from the battery to the coil and cranking to see if you get a spark, youcould end up causing more damage if a fuse has already blown to protect the ignition system from ashort circuit.


12/27

16.You should make a serious effort to obtain the wiring diagram for the car before trying to ring out thecircuits backwards just by following wires. Modern cars all employ taped up up wiring bundles andharnesses, and the wire color coding can even change as it goes through splices inside the largeconnectors. Supplied with the wiring diagram, you'll be able to trace the circuit path and find the opencircuit preventing current from reaching the coil just by checking the voltages or continuity through

the connectors, without unwrapping any wire bundles or disconnecting any devices. The wiringdiagrams also make it much easier to physically locate short circuits that are causing a fuse or fuse -able link to blow. I've only had my car towed home twice, and the second time was due to a blown

fuse-able link I couldn't find the short for while standing around in the street. Turned out to be a wirefrom the crab switch that got crushed in between the crab and the air filter can months before, and

simply wore through due to vibration at the wrong moment.17.Is fuel getting to the last fuel filter in line? There may be three or four fuel filters in some cars, starting

with one in the gas tank and ending with a paper filter right before the crab or fuel injection unit. Thereare various ways to check for the presence of fuel flow to the final filter, professionals will use a gaugeto check the pressure and make sure it's up to specs. Another way is to remove the paper filter, see ifit's full of gas, and blow it out in the proper direction (flow goes towards the crab or fuel injector, there

should be an arrow on the filter). I just blow through the filter with my mouth, you might want to passon getting gasoline in your body, and its bad for you. If you can't blow through the filter, it's clogged.If there's no gas in it when you take it out, gas isn't getting there, which means either you're out of gas,you have a fuel pump failure, or you're suffering vapor lock or a blockage in the fuel line or previousfilter. I suppose you could also have a hole and be squirting gas all over, but you'd probably smell that.

18.Some folks test fuel pump operation by redirecting the output line into a container and cranking theengine to test the flow. Needless to say, if you're smoking or sparking, you could go up like a torch.Modern cars also have vented gas caps and complicated vapor recovery systems. If any of these blocksup, you could end up with a vacuum in the tank or in the vapor recovery system pulling pack on thegas that the fuel pump is trying to move forward. Release the gas cap and see if you get a big"whoosh" sound, after which the car starts or runs better.

19.Does the vehicle have electronic fuel injection or a carburateur? Fuel injected cars are subject toinjector failures or blockages that can result in all sorts of starting and running problems. You caneither have electronic multi-point fuel injection, where each cylinder of the engine is fed directly by afuel injector, or a single point fuel injector throttle body, which is sort of an intermediate step betweena carburateur and electronic fuel injection. You'll have to see a manual specific to the car model fordiagnosing fuel injector problems, from computer logic to supply voltage, etc.

20.If you have an old fashioned carburateur, you can try some engine starter fluid spray down the carbthroat (hold the throttle open) and see if it fires up. If it fires up and runs with the spray, you know youjust have a fuel or carb problem. Carburateurs do get junked up and carburateur cleaner is good stuff,but even if you spray it directly at the needle valve, it's not the same as taking the carb apart and

cleaning it. With the replacement gaskets, needle and accelerator pump in a rebuild kit, you can makequite a bit of difference. But I have over a quarter million miles and twenty plus years on my carb andnever had to rebuild it, so don't run to do it for no particular reason.

21.Does the car start, run a few seconds (or longer) and then stall? If the engine fires just a little but won'tcatch and get going, it could be anything in the spark control system, including timing, or it could bethat the engine needs to turn over a little faster to catch. If the car seems to crank very slow and fireswithout starting, it could be that the battery voltage is too low, the cables or connections are corroded,


13/27

or the starter is motor needs rebuilding. Try jump starting it even if your battery voltage looks OK, theextra boost should make it crank faster, and if you start right up, that's the problem

22.Check the OBD (On Board Diagnostic) or pre-OBD or OBD II code. Your owners manual may nothave this information, so check the aftermarket manual or shop manual. Many cars, in addition tohaving an OBD or OBD II connector that gives garages and inspection stations access to the engine

codes, can produce a failure code for various engine sensors and circuits by blinking a light in theinstrument cluster. The instruction for getting these codes will be specific to your car, often leadingyou to turn the key to "run" and "off" a couple times in quick succession. If the car runs and displays acheck engine light, some auto supply stores will check the stored codes for you in their parking lot.You can also buy a code reader for $70 or $100, depending on whether you just want the codenumbers or want a cryptic English message as well.

23.Does the engine fire right up but stall as soon as you release the key back to the "run" position? If sothere's a good chance it's the ignition switch that's failed, but they're expensive, so before you rush toreplace it, I'd get the schematic and ring out the system carefully. If you have an emergency, likeyou're out in the country being hunted by chainsaw wielding maniacs, you identify this problem, andyou have a couple minutes before they find you, you might hotwire the car, which really just means

connecting the run circuit so it's always on (eliminating the need for the switch)/ In some cars, thismight cause damage, leaving the run circuit active when the car isn't running, aside from running downthe battery, so I save it for life and death. Almost thirty years ago I had to rewire my Mustang after amajor meltdown behind the dash (from over cranking the starter after an engine change). When Ifinished the wiring job, everything worked and the car ran fine, but it wouldn't turn off, I'd accidentallyhotwired the car, connecting the coil positive directly to the battery, so once it was started it wouldn'tquit.

24.If the car stalls in the rain or in damp weather, it's very likely related the the high voltage section of theignition, the coil, wires, or distributor cap. It's just that much easier to arc out when the air is wet ratherthan dry, and it's a common indication of a cracked coil, cracked or loose distributor cap, or failingwires or boots when the car stalls or runs bad in the rain. Check by opening up the hood while the caris running at night (running in park or neutral with the brake on, that is) and see if there are sparksarcing anywhere in the engine compartment. There isn't some "right" level of arcing, all of it is bad.

25.If the car stalls and runs bad or won't restart after hitting a puddle, it's likely that water splashed all theway up to the distributor or coil, and is causing excessive arcing until it dries out. If the distributor ismounted at the front of the engine, it really should have a plastic shield over it. If getting out of the carand drying off the ignition parts with your T-shirt fixes the problem, you know the solution is replaceor shield those components, or avoid puddles from now on - without causing an accident.

26.If the car stalls warm, it could be something as simple as the idle being set wrong on an old car, orsomething as awful as a failing ignition computer on a new car. Check the standard fuel problemswhich can always lead to stalling, but vacuum leaks at the intake manifold or in any tubing can causestalling or lousy performance, as can any number of sensor failures. Newer cars are equipped with O 2sensors, MAP sensors (Manifold Absolute Pressure) and a dozen other sensors for combustionproducts and engine readings. Some sensor failures will prevent the car from starting, though theseshould show up in the OBD readings. Or sensors may misbehave, leading to poor running, hardstarting, or decreased gas mileage. One of the best indications that something is wrong is if your gasmileage falls in the absence of any changes in driving habits.

27.If the car stalls cold, the first thing to check is for a stuck choke, which may be letting too much freshair into the intake manifold. The EGR (Exhaust Gas Recirculation) valve is also suspect for cold


14/27

stalling problems, as are the ever present vacuum leaks, especially on older cars. My own habit is tosearch for vacuum leaks by spraying starter fluid at the vacuum lines and seeing if the engine surges(RPMs shoot up) meaning the spray has been sucked into the manifold through a leak. Of course, if ydo this with the engine hot, you may set the car or yourself on fire. In fact, even if you do it cold, youmight cause a fire or an explosion, I just don't own a vacuum gauge to check for leaks.

PROJECT 3

Aim:- Troubleshooting of Hardware PC.

Flowchart for Motherboard Troubleshooting


15/27


16/27

STEPS FOR MOTHERBOARD TROUBLESHOOTING FLOWCHART

Note that these steps correspond with decision points on the flowchart and are reached directly by clicking on thdiamond symbols. The text below cannot be read sequentially.

1. Do you get a live screen? A message saying "No Video Signal" or anything similar doesn't count as alive screen in this case. You need to get at least as far as a BIOS screen, either the system BIOS or anadapter BIOS loading.

2. Does the system power up? Do you hear any beeps, drives spinning up, fans, etc. If the power isn'tcoming on, proceed to Power Supply Failure. If the power supply diagnostics sent you back here,follow through these diagnostics as a double-check before giving up on the motherboard.

3. If you haven't performed the Video Failure diagnostics for a dead screen yet, do so now. Don't ignorethe obvious steps, like checking the power cord and the outlet. If you skip the video diagnostics andcontinue with the motherboard flowchart, you could easily end up buying replacement parts forhardware that's not bad.

4. One of the most common failures following motherboard or RAM upgrades is improper insertion of

memory modules. The levers should be lowered before inserting the memory module, and should raisethemselves up and lock in place when the module is correctly seated. If you're using obsolete RIMM(Rambus Inline Memory Module) memory, the modules in a bank must be matched, and you mustinstall CRIMMs (Continuity RIMMs) in the empty sockets. If you're using older SIMM (Single InlineMemory Modules), each bank needs a matched pair. In both cases, matched doesn't just mean capacityand speed, it also means manufacturer. I have a new page up for upgrading laptop memory withSODIMMs. For replacing regular DIMM memory, see the illustrated replacing RAM.

5. There are a number of reasons for a system with a good power supply to refuse to power up whichwere covered in the power supply diagnostics. Another reason is a failed CPU insertion, whether it's aslot or socket CPU. With good lighting, using a flashlight if necessary, make sure that any socket CPUis sitting dead flat in the socket, which means that the heat sink should be perfectly parallel to the

motherboard surface; the CPU may be so totally hidden beneath some heat sinks that you can't see theedges. This problem should really only be relevant if you just upgraded your CPU or installed a newmotherboard, because the CPU socket locks the CPU in firmly and the heat sink adds another level ofclamping. If a socket CPU is a new install, you have to remove the heat sink and CPU to visuallyinspect it for damage such as crushed or bent legs. A CPU will not seat correctly if the socket lockingarm wasn't raised all the way up before the CPU was inserted, or wasn't lowered all the way down

after. If your CPU won't sit down in the socket properly, either the socket is faulty or you have the

wrong CPU for the motherboard, I haven't seen a CPU creep out of a socket due to thermal shock forover a decade.

6. It's pretty tough to tell if old slot type CPUs are seated by visual inspection, so when in doubt, I reseatthem. On the plus side, you can remove and reseat a slot CPU without removing the heat sink, since

they form an integral unit. Make sure you correctly identify release levers on a slot CPU package,which are normally located at the top of the CPU package, to the inside of the motherboard supportstructure.

7. A stone dead CPU is another reason for a system to fail. All modern CPUs require a heatsink, andmost of these are an active heatsink, with a fan on top. You may encounter a heatsink without a fan inmass-manufactured brand-name systems where the manufacturer had the engineering talent in-houseto do a thorough thermal analysis and determined that the airflow over a passive finned heatsink was
http://www.fonerbooks.com/laptop_2.htmhttp://www.fonerbooks.com/r_ram.htmhttp://www.fonerbooks.com/r_ram.htmhttp://www.fonerbooks.com/laptop_2.htm


17/27

enough to keep the CPU within the operating temperature range. When there is a fan on the heatsink, itmust be hooked up to the correct power point on the motherboard for the BIOS to monitor itscondition and turn it off and on. If you just installed a new CPU and powered the system up with noheatsink, it may have failed already. If the fan on your active heatsink isn't spinning up, replace it andhope for the best. Make sure you see the new heatsink fan operating since it could be the power point o

the motherboard that's failed.8. If you have a system that powers up, the next question is, do you hear any beeps coming from themotherboard speaker. If your motherboard doesn't have an integrated piezoelectric speaker but doeshave a speaker connection next to the power and reset connections (usually the front, left-hand cornerof the motherboard) attach a case speaker. If you hear an unending string of beeps, it's often bad RAM,while a repeated sequence can be RAM or video. Other beep codes have been largely abandoned sincethey pertained to non-user replaceable surface mount components. Beeps or no beeps, I always reseatthe video adapter and the RAM, paying special attention to the locking levers on the memory sockets

9. Are your motherboard settings on the defaults? Whether you just put in a new motherboard or havebeen fooling around with overclocking, restore the default settings. This is often accomplished with asingle jumper or switch setting, but sometimes it involves moving several jumpers or switches. Get the

default values from the motherboard documentation. If you can't find the original manual or locate theequivalent documentation on the Internet, you may have to skip this procedure. Sometimes, the silkscreens on the motherboard are sufficiently detailed to work out the defaults, but you need really goodeyes to figure it out.

10.Although we're repeating a little of the power supply diagnostics here, stripping down the system is thenext step in a "no power-up" scenario. Unplug the power cord before each change in the case.Disconnect drives, one at a time, reconnecting power and trying power up after each. Next startremoving adapters, saving the video adapter for last, reconnecting power and retrying after eachchange to ensure you discover which component is causing the failure.

11.Running the motherboard without a case is a common technique used by technicians to eliminate anyweird grounding and shorting issues or mechanical stresses. It also makes it much easier to swap the

CPU if that's required. I normally do my bench testing on top of a cardboard box, with a static free bagor foam between the bottom of the motherboard and the cardboard. You don't walk away from a testlike this or you might come back to find the box on fire, If your motherboard powers up on the benchwith the same power supply that you used in the case, you have a geometry problem. Ideally, youshould have a spare power supply for bench testing if you're going to do regular repair and testingwork.

12.Make sure some standoffs aren't higher than others, putting unacceptable stress on the motherboard.Check that every standoff appears under a screw hole. The easiest way to be sure is to count the

standoffs, count the screws, and make sure there are no screws leftover after you install themotherboard. There could be a short caused by a misplaced standoff, a loose screw, metal chips fromshoddy materials. I've encountered standoff shorts that produce an endless string of beeps like RAMfailure, without damaging the motherboard. There's also the possibility that the case geometry is somessed up (out of square or level when the cover is forced on) that it's putting an unacceptablemechanical stress on the motherboard resulting in an open circuit. If you can't find the cause of theproblem, don't hesitate to try another case and power supply.

13.If you still have a "no power" situation with the motherboard running out of the case, there's alwaysthe last refuge of a scoundrel. Swap in a known good CPU not forgetting to install a good heat sinkand to connect the fan, even just for a quick test. I try to keep around some cheap old CPUs for this


18/27

purpose, just in case the motherboard is a CPU eater. It's another good reason to leave all themotherboard settings on the default "Automatic" setting, so you don't have to fool around with them atthis stage. If your old CPU is bad and the heat sink fan is dead, it's a pretty sure bet that the dead fancaused the CPU failure. If the heat sink fan is working, determining whether the CPU failure was due topoor heat sink contact, improper motherboard settings, or lousy power regulation from the

motherboard is a guessing game. If the motherboard is an older make and you have a couple bucks tospare, replace the CPU and the motherboard together. Replacing just the CPU, even if the motherboardtests out OK, is kind of risky and usually tough to justify from a price/performance standpoint unless thsystem was practically new, say less than a half a year old.

14.If you still have a no power situation, not to mention no beeps and no video, you're probably looking ata bad motherboard. Again, this diagnosis assumes that you went through the Video Failurediagnostics, which would have forced you through the Power Supply Failure diagnostics as well. I stillwouldn't be in a hurry to take a gun to the motherboard. Get your system operating with a replacementmotherboard and all the identical parts that the old motherboard failed with before you make the trashcan decision. I just added some illustrated instructions for replacing a motherboard to this site,including installing a new motherboard.

15.Does the system power right up, give a happy beep or two, then freeze on the BIOS screen? This canoccur on an all text screen, during or after memory count, while checking for drives, or the feared"Verifying DMI Data Pool." The problem is very likely due to a conflict, most like between theadapters but also possibly between incompatible drives sharing a bus.

16.Strip the system down to bare-bones, just a power supply, motherboard, minimum RAM, CPU andheat sink, and video adapter. If the system no longer freezes when it's stripped down, but complainsabout the lack of a boot device, proceed to Conflict Resolution.

17.Try swapping the RAM around, reordering the banks if you have more than one bank of RAMinstalled, or moving the only module installed to a neighboring slot. If this doesn't cure the freeze-up,and you have some suitable known good RAM from another system, try it. If the RAM currentlyinstalled doesn't meet the motherboard manufacturer specs, you shouldn't be using it; even if it seemed

to work until this point. Improperly selected RAM can be the cause of problems ranging from no -bootto intermittent lock-ups. Is the RAM seated correctly and in the proper quantities (i.e., number ofmodules, addition of continuity modules, or CRIMMs, if you are using RIMMs). Also make sure thatthe system didn't use tinned (silver color) contacts against gold contacts, or the dissimilar metals willcause corrosion over time due to a constant electrical current when the power is off. Replacing RAM atthis point isn't a guaranteed proposition, but it's a good item to eliminate. Don't toss out the RAM youremove because you may find out later that it's actually good.

18.If you aren't using the default CMOS settings, try restoring them all at this point. You can usuallyrestore these from a major CMOS menu item like "Restore Default Settings" or "BIOS DefaultSettings." The default settings usually put everything on autodetect and use the recommended timingfor the RAM. This means if you're overclocking, stop it, at least until you get the system runningagain. It doesn't matter whether or not overclocking the exact same CPU or RAM in a friend's systemworked without a hitch, you're exceeding the manufacturers recommendations so it's a gamble.

19.An overheating will cause the system to quickly lock up. Remove the existing heat sink and fan, makesure that the fan is working properly AND that the geometry of the bottom of the heat sink will bring itin full contact with the exposed CPU die or the top of the CPU package. See my illustrated guide forhow to replace a CPU. Apply an approved thermal grease or thermal tape before reinstalling the heatsink. Don't put on too much thermal grease or you'll just make a mess. The thermal media is only there
http://www.fonerbooks.com/r_mother.htmhttp://www.fonerbooks.com/r_board.htmhttp://www.fonerbooks.com/r_cpu.htmhttp://www.fonerbooks.com/r_cpu.htmhttp://www.fonerbooks.com/r_board.htmhttp://www.fonerbooks.com/r_mother.htm


19/27

to fill the microscopic gaps between the die surface and the heat sink. Don't improvise your thermalmaterial, go to a computer or electronics store and buy some. Installing heat sinks can be frustrating, buthis isn't a "bash away at it" process. You can damage the CPU if you start cracking the heat sink againit in an attempt to get the heasink to sit right. Be patient, study the mechanical connections, make sureyou aren't hitting some poorly placed component on the motherboard and check that your heat sink isn'

so oversized it just won't fit on the particular motherboard.20.Make sure the fan on that heat sink spins up the second that power comes on. If it doesn't, despitebeing connected to the correct power point (see the motherboard manual), replace it with a new activeheat sink unit. Make sure the bottom surface of the new unit will make full contact with the exposedCPU die or the top of the CPU package. The only problem with replacing an active heat sink is it maybe too late for your CPU. CPUs have an unfortunate tendency to damage themselves when theyoverheat. Some CPUs can go into thermal runaway and destroy themselves in a matter of secondswithout proper cooling.


20/27

PROJECT 4

Aim:- Sound Card Problem.

Flowchart for Sound Card Problem


21/27

STEPS FOR SOUND CARD PROBLEMS FLOWCHART

Note that these steps correspond with decision points on the flowchart and are reached directly by clicking on th

diamond symbols. The text below cannot be read sequentially.

1. Do you get any audio out of the PC other than beeps on power-up? The beeps you hear on power-upare not part of the PC's sound system, they are generated by a tiny piezoelectric speaker on themotherboard that is included strictly for diagnostic codes. If you are getting any other audio from thePC, music, chimes, etc, the sound hardware hasn't failed, so you can proceed to the sound performanceflowchart. I just posted a page that looks at some laptop sound problem issues.

2. Is sound enabled in the operating system? In Windows, the basic "Sounds" menu is found in ControlPanel. Sound events that have little speakers next to them are enabled. Enable sounds for some actionsthat you recognize (like "exit program" or "minimize") and see if your speakers work now. Note thatoperating system sounds don't need to be enabled for music CDs or games to work, but if you're here,we're starting off with the assumption that you aren't getting any sound out of the speakers at all.

3. Are the speakers plugged in to a power source? The volume control on speakers usually serves as an

on/off as well. There are some super cheap speakers that don't offer amplification, in which case therewon't be any power cord, but don't expect much in terms of volume or quality. Really ancient speakersmay be powered by batteries rather than a transformer, so if your speakers don't have a power cord,double check that they don't have a hatch for batteries.

4. The oldest sound cards have a manual volume dial, as do most external speakers. Manual volume dialsshould be adjusted to somewhere in the middle of the range, not all the way to one extreme or theother. Did you check? Check again. You don't want to invite a friend over to help with your sound

problem, only to find the volume is manually turned down.5. Have you loaded the best driver for the sound card? The best driver means the most recent driver, so

check the manufacturer's website for an update, because your sound card may have been sitting on ashelf for a year before you bought it. If the sound is integrated on the motherboard, check for an update

at your motherboard manufacturer's web site.6. Does Device Manager register the sound card or integrated motherboard audio and report that the

device is working properly? Even if you don't have the proper driver, Device Manager will probablyidentify it as a sound controller. Before you start stripping down the system or chase off to conflictresolution, make sure the adapter is seated in the motherboard slot.

7. If the Device Manager reports a resource conflict between any of the audio devices and another device,look through all of your device reports and figure out where the conflict is. It may be resolvable bychanging the settings in Device Manager, or it may take aggressive reshuffling of adapters. If you get a",," "?" or "i" on the sound controller in Device Manager, proceed to Conflict Resolution.

8. Check your documentation or the symbols on the sound card to make sure you actually have thespeakers plugged into the proper jack. On high-end sound cards with front and rear speaker jacks, try

the front speaker jack first. Check that your audio patch cables are all plugged firmly into the properjacks and that the cables aren't damaged. If you have USB speakers, they don't jack directly into thesound card.

9. If you are using USB speakers or a full USB sound card, try connecting them to a different USB port.USB ports often break inside the PC when the cords are jerked or tripped over. If you can't get the

USB sound device to function on the PC, test it on any other PC or laptop. If it works on another

computer, you know that the problem is either that all of your USB ports have failed, which woul
http://www.fonerbooks.com/speakers.htmhttp://www.fonerbooks.com/speakers.htm


22/27

usually mean the USB controller on the motherboard popped, that the driver software is incompatible, orthat you didn't find a "mute" in the OS.

10.Software volume controls are the #1 problem with sound, and a real pain to figure out if multiplepeople use the system. Aside from the primary volume control often found in your system tray, thereare various other mixer panels and volume adjustments that get installed with the driver and are

offered in various applications. All of these can cause a complete absence of sound if the "mute" box ischecked. I don't have any magic method for finding the mixer panel or any additional volume controls in atypical system. The Multimedia icon in Control Panel is a good place to start.

11.Does your sound system work properly with everything except music CDs? If so, proceed to CD andDVD Playback diagnostics. One good test is to try the speakers and cables on another system, oranother device with a speaker jack, like a portable radio. Make sure you first turn the speaker volumecontrol all the way down in case the output is already amplified. If your speakers and cables don'twork anywhere, try swapping the cables to find out which is faulty. If the speakers and cables aregood, either the sound card is blown or you didn't look hard enough for a hidden mute in software.

12.If Device Manager only registers the sound card when you strip out all the adapters except the videocard, it's definitely a conflict. If it's a new build or a new sound card, make sure you followed the

installation instructions, which may have specified that you must install the software before installingthe hardware. If that was the case and you did it backwards, remove the sound card, uninstall thesoftware through Windows Control Panel > Add/Remove Programs, and start over. If you haveanother sound card lying around, it's a good time to replace the sound card; otherwise proceed toConflict Resolution.

13.If your only audio support is built into the motherboard, make sure it's enabled in CMOS Setup. If youare using a sound card, make sure any motherboard audio is disabled in CMOS Setup. The easiest wayto replace a motherboard integrated sound card is to pick up USB speakers (the sound card is built intothe speakers) or a full USB sound hub. The only potential problem with these is if you have an olderCD or DVD drive that doesn't support DAE (Digital Audio Extraction). Without DAE, USB sounddevices won't be able to play music CDs.

14.If you can't get the operating system to recognize an installed sound card, which is sure to be plug -and-play,shut down and unplug, remove all the other adapters except the video card from the system, reboot and let

the BIOS and operating system adjust. Then shut down and unplug again, add the sound card, and see if you

can get it going.
http://www.fonerbooks.com/r_sound.htmhttp://www.fonerbooks.com/r_sound.htm


23/27

PROJECT5Aim:- Video Card Problem.

Flowchart for Video Card Problem


24/27

STEPS FOR VIDEO CARD PROBLEM FLOWCHART

Note that these steps correspond with decision points on the flowchart and are reached directly by clicking on th

diamond symbols. The text below cannot be read sequentially.

1. Is the system power coming on? Can you hear fans turning and drive motors spinning up, see littlelights on the front of the CPU case, hear any beeps? We're talking about system power here, not themonitor power. If the system isn't powering up, or if you aren't sure whether or not it is, go to the

Power Supply Failure chart now.2. Does anything at all show up on the screen with the monitor power on, or is it just as black as before

you powered on the CPU? We aren't demanding any signs of intelligent life in this case, any sign oflife will do.

3. Assuming the system power comes up; does the monitor power come on? Monitors have a status LEDon the front bezel that should show green, orange, or blinking if the monitor is powered on. You canalso hear older monitors power on with a gentle sound, though I can't describe it beyond saying it's thesound of a CRT tube warming up. Make sure the monitor is plugged into a good outlet by testing the

outlet with a lamp or any other device that will prove beyond a doubt that the outlet is good. Make surethat the power cord is either permanently attached at the monitor end or that it is seated fully in thesocket, since partial cord insertion is the most common failure for monitors with detachable cords.

4. LCD displays don't make any sound when you turn them on, but they don't always have a simplepower cord, either. Some LCD monitors are powered by an external transformer, which in turn ispowered from a regular AC outlet. If the LCD display doesn't show any signs of life, make sure thatthe cords into and out of the transformer are fully seated. Some transformers are equipped with a statusLED to show when they are operating, though you can also check for live output with a DC voltmeter.The power connection to the LCD display is often awkward to inspect, recessed into the back of thedisplay. The important thing is to make sure it is started correctly, then seat it all the way.

5. Few things related to computers are more embarrassing than taking your monitor for repair and finding

out that the brightness was turned all the way down. This frequently happens with exposed dials whenyou pick up the monitor and move it, though a prankster might also turn down the settings whenthey're concealed behind a pop-out door right under the screen. Make sure that manual brightness andcontrast controls on the monitor are set somewhere in the middle of their range, since it's not alwaysobvious which way is maximum or minimum. If the monitor is alive, turning the brightness andcontrast all the way up will often result in the screen lighting up a little. The easiest way to check if themonitor is good is to simply attach it to another working PC.

6. If you see a message on the screen that includes "power" in it, like: "attach graphics card power", "nopower to video adapter", etc, it means that you have a PCI Express or older AGP video card that

requires more power than the motherboard can supply through the bus. This means you need to run apower cable directly from the power supply to the video adapter, inside the PC. If it's a new build, you

may have forgotten or not seated the connector firmly. If it was a working PC, either the power supplylead has failed, the power supply itself has problems, the cable worked loose, or some hardware on thevideo card has failed.

7. Earlier video cards that required additional power from the power supply usually took a Molexconnector, the same 4 pin connector used to power non-SATA drives. Newer power supplies includeone or two six pin PCI Express supplementary connectors designed for power hungry graphics cards.


25/27

Some PCI Express cards, in the absence of a six pin supplementary lead, will accept two 4 pin Molexleads.

8. Most new monitors will display something such as "No signal source," or "Attach video signal," aslong as they are healthy, and powered on. These messages should appear even if the PC or videoadapter is dead. This is actually one of the more useful innovations in monitor technology, because it

offers definitive proof that the monitor or LCD display is alive and most likely capable of displayingan image if a video signal was present. Unfortunately, it only proves something by its presence, sinceolder monitors and cheaper models may not display anything at all.

9. Make sure the 15 pin video signal cable (3 rows of 5 pins each for SVGA) is seated squarely on thevideo port on the back of the system. The hold-down screws on either side of the connector should bescrewed in all the way, but not made up too tight. If the video cable is connected correctly, remove itand inspect the connector for damage.

10.Before making yourself nuts, test the monitor on another PC or laptop. If you use a laptop to test themonitor and it doesn't automatically detect an external monitor when booting, use the "F" functionkeys along the top of the keyboard to tell the laptop to shift to the external display. Remember that weare testing just to see if the monitor is live, it doesn't matter if the screen settings are wrong and the

display looks funny. If it doesn't work on a known good computer, the problem is with the monitor,not your PC. If a faint image is detectable on an LCD screen, the problem is with the backlight or theinverter that powers the backlight. A loud buzz coming from an LCD monitor is most likely theinverter circuit failing, though it can go on getting louder for years before it pops.

11.Look carefully at the pins in the connector to make sure none of them are at an angle or flattenedagainst the bottom. Note that missing pins in a video cable are the norm, usually the monitor ID pins.It's great if you have a spare video cable and a monitor with a detachable cable, but most monitors

have an integrated cable (doesn't detach) and most people don't have a spare anyway. You'll usuallyhave to settle for visual inspection for whether the cable may have been crushed or breached.

12.If you see that a pin in the connector is bent, you can try to straighten it very slowly with tweezers orfine needle nose pliers. If a pin breaks, you can buy a replacement connector and solder it on with a

fine soldering iron and infinite patience. You'll also need a heat shrink gun and tubing if you want todo it right. The last time I did one it took me almost three hours, though I didn't really have the rightsoldering iron tip. I don't recommend making your own DVI connector.

Video Connector Pin out

1-Red2-Green3-Blue

4-Monitor ID (Note: pins for ID bits often not present)5-Ground

6-Red Return (coax shield)7-Green Return (coax shield)8-Blue Return (coax shield)

9 No-Connection10-Sync Ground

11-Monitor ID12-Monitor ID


26/27

13-Horizontal-Sync14-Vertical-Sync

15-Monitor ID

13.Do you hear a string of beeps? Healthy PCs should beep once or twicewhen they are turned on and

pass their Power on Self Test (POST) routine. While different BIOSmanufacturers use different beep

codes to identify failures, a repeating string of beeps (three or nine in a row)is a common indicator of

video card failure.

14.Check whether or not the video adapter is properly seated. This is an in-the-box check, so make sureyou unplug the power cord to the system first. This doesn't apply to

motherboards with built-in video.Whether or not the video adapter appears to be seated properly, reseat it.

Remove the video adapterhold-down screw, remove the adapter, then reseat it in the slot, pushing

down evenly. Be careful thatputting the hold-down screw back in doesn't lever the front edge of the

video adapter (the end awayfrom the screw) up a fraction of an inch out of the slot, because that's all it

takes if there's no hold -down latch.

15.If reseating the card doesn't clear up the beeps, it's probably a failed videoadapter or RAM on the

motherboard. You can power down and try reseating the RAM at this point,without going all the way

through the motherboard diagnostics. There used to be beep codes for allsorts of component failures,

but most of those components have long since been integrated into themotherboard and can't be

replaced if they fail.

16.Does the system get as far as showing the BIOS screen and locking up? By BIOSscreen, we're talkingabout the text information or brand-name graphics that appear on the screenin the initial boot stages. A system that freezes up at this point is rarelysuffering from a video failure, though a conflict between the video card andanother installed adapter is still possible.

17.Did you install any new adapters immediately before the problemappeared? With the power


27/27

disconnected, remove any other adapters, one at a time, then reconnectpower and attempt to reboot

after each removal. Locking up on the BIOS screen is often due to anadapter conflict, but if removing

the other adapters doesn't solve the problem, proceed to Motherboard, CPU

and RAM Failure.18.Do you get a live screen, or at least move past the BIOS screen, with all theother adapters removed? If

so, the problem is either a bad adapter preventing proper operation of thebus or an adapter conflicting

with the video card. In either case, you can reinstall the adapters one at atime, powering up after each

one, troubleshooting the problem by process of elimination. Don't forgetto unplug the system each

time before taking any action inside the case.19.If the motherboard is a new upgrade, try the video adapter in another systembefore trashing it, since it

could be a simple incompatibility. If installing a new video adapter doesn'tsolve your "dead screen"

problem, it's probably a motherboard related problem, even though you gotto this point without any

beep codes. Proceed to Motherboard, CPU and RAM Failure. I just addedan illustrated guide for how

to replace an AGP video adapter to the site.
http://www.fonerbooks.com/r_video.htmhttp://www.fonerbooks.com/r_video.htmhttp://www.fonerbooks.com/r_video.htmhttp://www.fonerbooks.com/r_video.htm

Documents

Es Lab Final