MICROLINE. 280TROUBLESHOOTING MANUAL

WithCOMPONENT PARTS LIST

PREFACEThis manual describes the component level troubleshooting and repair process for the Ml280.

TROUBLESHOOTING MANUAL

CONTENTS

1. Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l - l

2. Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l - l

3. Troubleshooting Procedure ............................................... l-2

4. Troubleshooting Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1 Outline

Gelleral

This troubleshooting manual is designed to locate and repair problems

on a component level for the INDU-printed-circuit boards and other

printer components.

1.1 Remarks

This manual requires basic knowledge of electronic circuits.

.

\-.

.

Use chip-dedicated soldering irons (such as Ungar soldering irons)

since the printed-circuit boards of the ML280 have heat-destructible

components (chips, packages, etc.). (Soldering irons for flat packages

are widely available.)

Be careful not to break any wiring etched trace patterns on the

printed-circuit boards while replacing components.

2 TOOlS

In addition to the tools listed in the printer's Maintenance manual,

the following tools are required for repair of components on the

printed-circuit boards:

. Extension cord (OKI Part No. 3YU5003-5010Gl or equivalent)

a Oscilloscope

. Soldering iron (with fine tip) ’ commercially available

l Solder wick I

l-l

3 Troubleshoot ing Procedure

Troublesboot by thegeneral flowchart Note 2

Sqmir tile failureaccordInS to theassociated repairf 1owc,,nrt

Run ebe printer for ap r e d e t e r m i n e d t i m ewithout stopping.

N o t e s 1: Visually check the defective printed-circuit board before

mounting it on the printer.

2: If the printer or the printed-circuit board is returned along

with an error report, first check the reported failure.

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4 Troubleshooting Flowchart

4.1 General Flowchart

1-3

I I

Note: PITCH and MODE switches are valid during select and deselect states.

?-,

1-4

1-5

1 NO

1-6

Note: This step is required since parts are overloaded if powerrepeatedly suppl ied wi th the de fec t ive dr iver parts .

1 -7

Replace MD” Replace TR3

bvnt collector Of Replace TR4

J

1-8

When power is turned on, Fuse (Fl) on the INDU board blows.

No

the proper ly ratedf u s e i n s t a l l e d ? I

Replace with a properlyrated fuse .(1.5 A)

Measure the resistanceb e t w e e n +8 V line andgrmuld.

Measure Ck resistancebatween +5 V l ine andground.

I

Replace the REG andTR14

l-9

2. Power supply circuit

02-I AC circuit and rransforner

_I

l-10

DC +30 " circuit

Check and replacediodes D8.D9,DlOand Dll if faulty

I

l-11

3. p CPU circuit

2: The level of each of the output signals should not be at halflevel (about 2 to 3 V).

1-12

4. SP motor drive circuit

Paulty homing operation

I

Replace TR3,HKJV and QL

Note: The phase of the line-feed motor is adjusted when a space-homing ismade at power on. Turn on the POWER switch while touching theplaten knob. When you feel the platen knob rotate, the CPU circuitis normal.

1-13

Replace the MTDV.

NO

IR e p l a c e TR6,Ll

Replace thc.SP Notor.

1-14

Notes 1 : MTDV operation:

SPD-A pulse signal from the MTDV-6

through buffer 1 and comparator 2,

switching c ircui t (TR3, Ll, D6 and

is output to the MTDV-2

smoothed by the choppier

U), then led as a

phase-driving voltage to the MTDV-1.

2 : Coil current protector

When a current flows through a phase, voltage drop at resistor

R7 is generated by current i . If the voltage drop becomes higher

than the voltage at the MTDV-4, the limiter 3 and buffer 1 are

powered off . Thus, the MTDV is powered off.

3 : Voltage protector. If the voltage generated in the chopper

switching circuit exceeds 30 V, comparator 2 is powered off.

I Remove paper. I

1-16

Turn the Power switchon.

1 - 17

PITCH L a m p 10 or 12 or 17 does not l ight

Turn the power s w i t c h0 ” .

Check connector connection.Replace Lamp 10,

TR3 (SLSX b o a r d ) ,92 (SLSX b o a r d ) , a n dQ4 (INDU board) .

Depress PITCH s w i t c h .

NOI s L a m p 1 2 o n ?eY e s

Check connector connection.Replace Lamp 1 2 ,

Q, (SLSX b o a r d ) ,Q 2 (SLSX board) ,Ql (SLSX b o a r d ) , a n dQ4 (INDU board).

C h e c k c o n n e c t o r c o n n e c t i o n .Replace Lamp 17.

Q 3 GLSX board) ,Q2 (SLSX b o a r d ) ,Ql (SLSX b o a r d ) , a n dQ 4 (INDU board) .

-\ !

-4

I EndI

O(5-5 NODE Lamp NLQ or UTILITY or “SD does not light

I

NO

Check ConneCtor connection.Replace UTILITY Lap,

Q3 (SLSX board) ,Q2 (SLSX b o a r d ) , a n dQ4 (INDU b o a r d ) .

Depress NODE switch.

I EndI

1 - 19

6. Switch circuit

suitdl does not operateI

-1

l-20

7. Line feed mator circuit

O(7-l Does no? perform line feed operation

I

Replace TR&, ~~13 .

L

LF Timing chart

,'

1-21

Note: Measure the resistance of each printhead, it should be about ZOQ._I

1-22

i-- O(8-2 some dots are not printed.

.-

Note:

1-23

Head ON

Head 1 to 9 X X' _IQ7-6Threshold

level

I

47-l I I I I I 1TR502-C

Head drivecurrent

1-24

9. Interface (Receiving)

O(9-1 Does not print at all.

I

Replace 94 or 93.

1-25

1 - 2 6

I II

l-27

1 0 . SASF o p e r a t i o n

O(10 Paper does not f e e d to print position (SASF functfon).

Turn off !xwer. remove INDU board, openbail arm, and measure the resistance betweenconnection board pins 20 and 24,

resistance 0

II

Replace INDU board.

1 - 2 8

COMPONENT PARTS LIST

Drawing List

INDU-Printed Circuit Board 4YA4050-2881Gxxx _. _. _. l - l

0

(

INDU-Printed Circuit Board with ROM 4YA4050-2881G3 (IBM) 1-5

l INDU-Printed Circuit Board without ROM 4YA4050-2881Gll ____________..__ 1 - 1 3

SLSX-Printed Circuit Board 4YA4050-2155Gl _____________._._ 1 - 2 1

SLPB-2.3 Printed Circuit Board 3YU5003-5611GZlG3 _. _. 1-25

._

ROM identification Chart by G No.

GNo. 1 ROM-No. 1 ROM Dart No. ROM Label t ADDlicatiOn 1 Remarks 1

GO03 1 08 1 4YR4067-7145Gl 1 67-7145 I For INDU I IBM I

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Figure 1 INDU-Printed Circuit Board (4YA4050-2881Gxxx) l/2 (l/2)

l-1