IDTV

CE37LD81-B CE42LD81-B

SANYO LCD TV

OVERVIEW &

FAULT DIAGNOSIS

17MB22 Chassis

SANYO LCD TV 2007-8

PCB Spares Listing

For the 2007-8 SANYO TV, ordering of spare parts needs reference taken not only of the TV model number i.e. CE37LD81-B but also of the actual Product Code and Production Code (Batch Number) of that particular model. On occasions the same model number could have a different particular Pcb or a different manufacturer or revision of LCD panel fitted. The Product code and Production Code could be viewed similarly to previous models whereby production changes were notified by use of a different service code i.e. CE32LD6-B-01. The required codes can be easily found on the rating plate on the TV back cabinet under the Model number and 2 bar codes as seen below.

Product Code

Identification of Production Code (26” Example)

During a production run with a particular Product Code, different LCD panels or Pcb’s may be fitted. Each of the changes will have a particular Production Code or Batch Number. (Shown above in blue). Therefore the correct ‘Product Code’ and ‘Production Code numbers’ must be used to locate the correct part numbers, otherwise incorrect parts may be supplied. Display Panel Inverter and Control Pcb’s will be supplied subject to availability. You must consult the appropriate parts list table for information before ordering any parts, otherwise incorrect parts may be supplied.

Production Code (Batch No.)

TV RATING PLATE

Signal Pcb (Chassis) Identification (42” Example)

Cabinet Back Rating Plate

Product Code Part Number

LCD Panel Size - 42”

Main (Chassis) Pcb

LCD Panel Manufacturer (LG in this example)

Production Code (Batch No.) 2 + 1st 7 digits of SN

This shows pcb correct for this model

• LCD Display Panel Replaceable only with prior TECHNICAL AUTHORISATION.

Inverter (Back Light) Pcb

Display Control Pcb (fitted inside rear of LCD Panel) (Both supplied as part of LCD Panel but available as spare separately).

• Signal Pcb - spares name - Chassis

• RCU / LED Pcb - spares name - LED Board

• Digital Freeview Pcb - spares name - DTT Board

• Power Supply Pcb - spares name - Power Board

• HDMI Pcb - spares name - HDMI Input Board

• AV Pcb - spares name - FAV Board

• Key Pcb - spares name - Key Board

TV Model: CE37LD81-B

GENERIC USE ONLY - See Spares ordering pages

Master Inverter

Signal Pcb (Audio/ Video / CPU & Scaler)

Power Supply Pcb Digital Freeview Pcb

RCU & LED Pcb

HDMI Pcb

Key Pcb

AV Pcb

Slave Inverter

Display Control Pcb

C902

PL809 AC IN

F800T2.5A

PL803 to Signal PL003 PL805 to PL002 Signal Pcb +24V to PL001 Signal Pcb

PL804 to Digital Pcb

37" POWER SUPPLY PCB

12V Run

3v3 5V Standby

4v9 3v3Run Supplies

PL802 to Master Inverter

Run Supplies

32V Stby34V Run

11v9 Run3v2 2v5 2v51v7 Stby0.6V Run

+24V 2v3 3v2Run Supplies

CE37LD81-B POWER SUPPLY PCB

Run Supplies

TR803STANDBYSUPPLIES

TR806RESONANT

CHOKE

PL811 to Standby button

7.8V (pulsing) Standby (front LED lit)0V Side Standby Key button pressed in

All other Voltages shown are with reference to the isolated metal chassis

TR805

RUN SUPPLIES

+

390V Run340v StbyREF UNISOLATED GROUND

Note :- This model has a low power mode, which switches off the CPU standby supplies and front LED, when the latching side standby key button is pressed. (The TV will appear completely 'Dead' and cannot not be operated by the RCU).In this mode 340VDC is still supplied by the bridge rectifier to the unisolated primary components, which are still Live..

PL801+24V Run to Slave Inverter

To PL302Digital Pcb

PL602 to LED / RCU Pcb

37" Signal Processing17MB22

TU100Combined UHF /

VHF / CATV Analogue & Digital

TunerPC

AUDIN Y Pb Pr L

AUDR

AUD

RGB, Composite Video inComposite Video Mon out

SCART 1

RGB, Composite Video inSVHS INSCART 2

L/SL/SFPC connector to Digital PcbAudio, Video & Control Bus

PL406

IF out to DigitalPcb

PL403 toKeypad Pcb

2 x HDMI 1.1 Pcb

Pc Input

To PL104 FAV Pcb

PL002 to PSU PL805 PL003 to PSU PL803

Component Video / Audio Inputs SrvPort

Service Port To Digital Pcb(LD Only)

IC400VCTP

Main CPU, VideoTXT, Audio, Scaler

IC702HDMI 1.1

LVDS Drives & Clocks measure 200mv on 100MHz Scope using x 10 probe.These may be very low or look non existent on a low bandwidth scopeIf all LVDS drives are present, the clock signals can be assumed to be OK.(See LVDS / Clock waveform pages)

12V LCD Panel Supplies

- + - + - + CLK - + LVDS Drives to LCD Panel

PL206

IC 101AGC

IC100Analogue

IF & CVBS out

IC405Sync

Switch

IC200

PC in

PL411

PL001 To PL801 PSU

11V9Run

32V Stby34V Run 1V7 Stby

0.6V Run

3V2Run

2v5Run

2V5Run

5VStby

3V3Stby

4V9Run

3V3 Run

IC601Audio Output

IC903RGB

IC902VideoSwitch

IC904AudioSwitch

IC905AudioSW

To PL205FAV Pcb

To PL204FAV Pcb

24VRun

IC001

3V3Stby

1V8Stby

0.6V Stby

IC00412V Run

10V5 Run 9.1VRun

CE37LD81-B SIGNAL PCB

Side Key PressNorm = 3v3

AV = 2VMenu = 0.56VCH+ = 1VCH - + 2v3Vol + = 1v6Vol - = 0.19V

IC 403NVM(64K)

LED 4v3 Run3v2 Stby3v9 (Dips with RCU)Always +5V

PL207

• LCD Display Panel Replaceable only with prior TECHNICAL AUTHORISATION.

Inverter (Back Light) Pcb

Display Control Pcb (fitted inside rear of LCD Panel) (Both supplied as part of LCD Panel but available as spare separately).

• Signal Pcb - spares name - Chassis

• RCU / LED Pcb - spares name - LED Board

• Digital Freeview Pcb - spares name - DTT Board

• Power Supply Pcb - spares name - Power Board

• HDMI Pcb - spares name - HDMI Input Board

• AV Pcb - spares name - FAV Board

• Key Pcb - spares name - Key Board

TV Model: CE42LD81-B

GENERIC USE ONLY - See spares ordering pages

Master Inverter

Signal Pcb (Audio/ Video / CPU & Scaler)

Power Supply Pcb Digital Freeview Pcb

RCU & LED Pcb

HDMI Pcb

Key Pcb

AV Pcb

Slave Inverter

Display Control Pcb

C902

PL809 AC IN

F800T2.5A

PL803 to Signal PL003 PL805 to PL002 Signal Pcb24V to PL001 Signal Pcb

42" POWER SUPPLY PCB

3v3 5V Standby

4v9 3v3Run Supplies

PL802 to Inverter Pcb

Run Supplies

34V Run32v Stby

11v9 Run3v2 1.7V Stby 0.6V Run

+24V

CE42LD81-B POWER SUPPLY PCB

Run Supplies

2v7

TR803STANDBYSUPPLIES

TR806RESONANT

CHOKE

2v7

TR805

RUNSUPPLIES

PL807 to Digital Pcb

12V RunPL811 to Standby button

8V (pulsimg) Standby (front LED lit)0V Side Standby Key button pressed in

+24V Run to Inverter

Note :- This model has a low power mode, which switches off the CPU standby supplies and front LED, when the latching side standby key button is pressed. (The TV will appear completely 'Dead' and cannot not be operated by the RCU).In this mode 340VDC is still supplied by the bridge rectifier to the unisolated primary components, which are still Live.

+

PL801

2v5

2v7 3v2

390V Run340v StbyREF UNISOLATED GROUND

All other Voltages shown are with reference to the isolated matal chassis

To PL302Digital Pcb

PL602 to LED / RCU Pcb

42" Signal Processing17MB22

TU100Combined UHF /

VHF / CATV Analogue & Digital

TunerPC

AUDIN Y Pb Pr L

AUDR

AUD

RGB, Composite Video inComposite Video Mon out

SCART 1

RGB, Composite Video inSVHS INSCART 2

L/SL/SFPC connector to Digital PcbAudio, Video & Control Bus

PL406

IF out to DigitalPcb

PL403 toKeypad Pcb

2 x HDMI 1.1 Pcb

Pc Input

To PL104 FAV Pcb

PL002 to PSU PL805 PL003 to PSU PL803

Component Video / Audio Inputs SrvPort

Service Port To Digital Pcb(LD Only)

IC400VCTP

Main CPU, VideoTXT, Audio, Scaler

IC702HDMI 1.1

LVDS Drives & Clocks measure 200mv on 100MHz Scope using x 10 probe.These may be very low or look non existent on a low bandwidth scopeIf all LVDS drives are present, the clock signals can be assumed to be OK.(See LVDS / Clock waveform pages)

12V LCD Panel Supplies

- + - + - + CLK - + LVDS Drives to LCD Panel

PL206

IC 101AGC

IC100Analogue

IF & CVBS out

IC405Sync

Switch

IC200

PC in

PL411

PL001 To PL801 PSU

11V9Run

32V Stby34V Run 1.7V Stby

0.6V Run

3V2Run

2v7Run

2V5Run

5VStby

3V3Stby

4V9Run

3V3 Run

IC601Audio Output

IC903RGB

IC902VideoSwitch

IC904AudioSwitch

IC905AudioSW

To PL205FAV Pcb

To PL204FAV Pcb

24VRun

IC001

3V3Stby

1V8Stby

0.6V Stby

IC00412V Run

10V5 Run 9.1VRun

CE42LD81-B SIGNAL PCB

Side Key PressNorm = 3v3

AV = 2VMenu = 0.56VCH+ = 1VCH - + 2v3Vol + = 1v6Vol - = 0.19V

IC 403NVM(64K)

LED 4v3 Run3v2 Stby3v9 (Dips with RCU)Always +5V

PL207

PL400Ground to PL802PSU

Digital Freeview Decoder

Card Reader

PL202 FPC to Signal PCB PL207

To Signal PCB (IF IN)

+12V from PL804 PSU

SPDIF out toFAV Pcb

From Signal Pcb Service Port

PL103

PL302PL501

PL102

IC 101

IC202

Audio / Video / Control Bus The Digital IF signal is fed into PL302 from the combined Analogue / Digital tuner assembly on the signal Pcb on the 'D' series models.

The +12V power to PL501 is always present from plug PL804 on the main power supply.

PL102 is connected to the Signal Pcb service port, by PL411 and allows firmware updates to the Digital Processor IC.

The FPC, flexible printed circuit connector from PL202, allows Audio & Video data and also control bus operation from PL207 on the signal Pcb.

PL103 supplies the SPDIF (Sony Philips Digital Interface) signal to the FAV Pcb for connection to external equipment

UHF-VHF-CATV- DIGITAL TUNER ASSEMBLY

TU100

0V0V33.7V1.5V5V5V4V Varying with signal4V Varying with signal0V1.7V0.05V

All voltages measured in RUN mode with normal off air signal.

Low Voltage Difference Signal Waveforms

Figure 1 – Negative LVDS waveform example This waveform is an example of the differential signal which may be observed on the LVDS output plug. See Signal Pcb Diagram for specific pins. All negative pulses should be similar in amplitude and frequency (70-80Mhz). The signal has a DC level of between 1.125V and 1.375V depending upon the type of input signal.

Figure 2 – Positive LVDS waveform example This waveform compliments the negative version shown above; See Signal Pcb Diagram for specific pins. All positive pulses should be similar in amplitude and frequency (70-80Mhz). The signal has a DC level of between 1.125V and 1.375V depending upon the type of input signal.

Low Voltage Difference Signal Clock Waveforms

Figure 3 – LVDS clock waveform This waveform should be present in both positive and negative form on the LVDS output plug . See the Signal Pcb Diagram for specific pins. The clock frequency is specified as 74.25MHz but may be anywhere between 70MHz and 80MHz. The waveform has an offset of approximately 1V DC.

The LVDS clock waveforms Please note that there are normally two of these clock signals present and as these are 70-80Mhz waveforms they may look to be non existent or very low in amplitude if a low bandwidth oscilloscope is used. i.e. 20-50MHz. An 80-100Mhz Bandwidth oscilloscope will be required to display the correct Clock And LVDS drive signal amplitudes. If a higher bandwidth oscilloscope is not available and all other LVDS drive signals are present, then these two clock signals can be assumed to be OK.

NO SOUND OR PICTURE

Yes No

FAULTY SOUND - PICTURE OK

Dead Set or Stuck in Standby

Is front LED lit

Check 340V across C902 on PSU. If OK, Unplug side key standby button from PL811 on PSU. If TV operates OK. Replace Button. If no 340V, check T2.5A fuse on PSU. If fuse is blown and blows again, replace PSU.

If fuses OK, check for 240V AC at PL809 on PSU. If not present, check the mains lead & plug fuse.

If 240V AC Ok , check PSU Standby voltages at signal Pcb plugs PL002 and PL003.(See Signal Pcb diagram).

If voltages OK replace Signal Pcb. If incorrect then replace the PSU.

Check with RCU, if set comes on replace the TV Keypad Pcb.

If set comes on via the keypad, but not the RCU, then check the RCU and if OK, replace the LED / RCU Pcb.(see signal Pcb diagram PL602 for voltages)

Check Signal Pcb for all correct Standby voltages at PL002 and PL003. (See Signal PCB Diagram).

If incorrect check wiring to PSU, If OK, replace PSU PCB.

If OK replace the Signal Pcb.

No or Distorted Sound Output from all Sources

Check all Run voltage supplies from PSU at the Signal Pcb (See Signal Pcb Diagram)

If incorrect check PSU suppliesIf all OK. Replace faulty loudspeaker, or replace Signal Pcb.

Yes No

Yes No

NO PICTURE - NO OSD - SOUND OK

Are Backlights Lit ?

No Picture from TVor any AV inputs. No OSD. Sound OK

Check all voltages to the Inverter Pcb at PSU PL801 / PL802 and Run voltages at PL803 & PL805. (See PSU diagram)

If all voltages from the PSU are OK, check the inverter Pcbs for D/J or replace.

If after replacing the inverter Pcb, the backlights are still not lit, then one or more of the backlight lamps could be faulty.

If PSU voltages are incorrect, then replace PSU Pcb.

Check the five LCD panel +Ve supplies at Main Pcb LVDS LCD panel connector PL406.(See Signal Pcb diagram).

Also check all eight LVDS and two CLK waveforms with scope at LCD panel connector. (see Signal Pcb and LVDS diagrams)

If OK, do continuity check on LVDS cable.

If cable OK, try replacement display control pcb (top rear of LCD panel under metal cover). If still faulty then replace the LCD Panel assy.

If voltages / waveforms not OK then check all supplies on the Signal Pcb at PL002 and PL003. (see Signal Pcb diagram). If voltages OK, replace the Signal Pcb.

If voltages incorrect replace the PSU

If one channel of either of the inverters is not functioning due to a faulty inverter Pcb or a faulty lamp, then the backlights will light initially and then the inverter board will shut down with no picture, but the sound will still be present if previously tuned in.

Produced in the UK by

Mike Burnett Senior Technical Liaison & Training Engineer

SANYO Europe Ltd