Panasonic TC-32LX70, TC-32LX700, TC-37LZ85, TC-32LX85 Technical Guide

Panasonic Service and Technology Company

Technical Guide

TC-32LX70/700, TC37LZ85, and TC-32LX85 LCD Display Television

National Training

Prepared by

Jean Magloire

Panasonic Service and Technology Company

National Training

Warning

This service information is designed fo r experienced repair technic ians only and is not designed for use by the general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to servic e a product. Products powered by electricity should be serviced or repaired only by experienced pro fessional technicians. Any attempt to service o r repair the product or products dealt with in this service information by anyone else could result in serious injury or death.

Table of Contents

Subject Page # Subject Page #

Topics 5 Self-Check Menu 38 2007 LCD TV Specifications 7 Check Point 39 P.C.B Layout (LX700) 8 Serviceman Mode 40 P.C.B Layout (LX70) 9 Serviceman Mode Menu and Navigation 41 P.C.B Layout (LX700 Pictorial) 10 Adjustment Data 42 P.C.B Layout (LX700 Connectors) 11 SRV-TOOL 43 P.C.B Layout (LX700 LVDS Connector) 12 Voltage chart of AP-board 45 TC-32LX700 Board Description 13 Voltage chart of P and A boards 46 P Board – Main Power Board 15 Voltage chart of DT board 47 Main MPU (Power On Commands) 17 Troubleshooting Signal Problems 49 Standby Operation 19 Picture NG and Sound OK (LX700/LX70 ) 50 SUB Voltages and Over-voltage Protection 21 Picture OK and Sound NG (LX700/LX70) 51 Main Voltages and Over-voltage Protection 22 Picture NG and Sound NG (LX700/LX70 ) 52 Inverter_On Command and Protection 23 No Picture from TV Reception 53 Video Process Block Diagram 25 No Picture 54 Audio Process Block Diagram 27 No Video, Dark Blue Screen 55 MPU SOS Inputs and Blink Codes 29 No Audio 57 Over-Current Protection Circuit 31 No Power 58 Over-Current Protection Circuit 2 33 Power LED Blinks One Time (INV_SOS) 60 Power LED Timing Table 35 Power LED Blinks Three Times (TV_SOS) 61 Self-Check and Reset Function 37 Power LED Blinks Four Times 62

3

Table of Contents

Purposely Left Blank

2008 LCD Television Models 63 Full HD TC-LZ85 & HD TC-LX85 Series 64 Chassis structure (37 Full HD type) 65 Chassis structure (37 HD type) 66 Signal Circuit Block Diagram 67 TC-32LX85 / TC37LZ85 Signal Circuit Block Diagram 68 TC37LZ85 Signal Circuit Block Diagram 69 TC32LX85 Signal Circuit Block Diagram 71 TC37LZ85 Audio Circuit Block Diagram 73 TC32LX85 Audio Circuit Block Diagram 75 Power Supply Overview 77 Power Supply Description 78 Self-Check and Reset Function 80 SOS and Power LED Indication 81

Power LED Blinks 6 or 7 Times 85 Power LED Blinks 8 or 9 Times 86 Power LED Blinks 1 Time (TC-32LX85) 87 Power LED Blinks 3 Times (TC-32LX85) 88 Power LED Blinks 4 or 5 Times (TC-32LX85) 89 Power LED Blinks 6 or 7 Times (TC-32LX85) 90 Power LED Blinks 8 or 9 Times (TC-32LX85) 91 Picture Defect) 92 Sound Defect 104 Service Information for 2008 models 105 Internal Pattern generator 106 Copy from the TV to the SD Card 109 Copy Data from the SD Card to the TV 115 Copy Self Check Data to the SD Card 117

Power LED Blinks 1 Time 82 Power LED Blinks 3 Times 83 Power LED Blinks 4 or 5 Times 84

Local maintenance 120 Picture Refresh Mode 128

4

Topics

1. Models Comparison

2. Boards Layout

3. Power supply/Standby/Power on

4. Troubleshooting

5. SOS Circuit

6. Video/Audio Processing Circuit

7. Panel Drive Circuit

8. Service Man Mode

9. Self-Check

10.Reset

11.Adjustments

12.Service Information for 2008 models

5

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6

2007 LCD TV Specifications

VIDEO

Screen Size Diagonal (inches) 32 32 Aspect Ratio 16:9 16:9 Number of Pixels 1,049,088 (1,366 x 768) 1,049,088 (1,366 x 768) Brightness (Panel Luminance) 500 cd/m2 500 cd/m2 Display Capability (1080p, 1080i, 720p, 480P) Y Y Motion Picture Pro Y —

AUDIO

Speakers Slim squawker x 2, woofer x 2 (L, R) Full-range x 2 (L, R) Audio Output 20 W (10% THD) 20 W (10% THD)

JACKS

TC-32LX700 TC-32LX70

Integrated ATSC Tuner Y Y SD Memory Card Slot Y (SDHC Compatible) — HDMI Input 2 2 Composite Video Input 3 (1 side) 3 (1 side) S-Video Input 2 2 Component Video Input (Y, P Monitor Output 1 1 Digital Audio Output 1 1 Headphone Jack 1 1

, PR ) 1 1

B

7

P.C.B Layout (LX700)

SP

G

SP

32/26LX600

KEY Control

AP

A

DT

(HDMI)

SP

P

V

SP

32LX700

SP

A

GS

G

SP

KEY Control

INV

AP

SP

P

DT

(HDMI)

SP

V

Differences from LX600:

GS board for SD card slot is added.

The inverter PCB of the LX700 is visible.

8

P.C.B Layout (LX70)

G

32/26LX60

KEY Control

A

(HDMI)

SP

AP

DT

P

SP

V

G

32/26LX70

KEY Control

AP

A

(HDMI)

SP

DT

P

SP

V

Differences from LX60:

Board structure is almost same.

9

P.C.B Layout (LX700 Pictorial)

GS Board

Key Control

A Board

AP Board

DT BoardG Board

10

P Board

V Board

Inverter PCB

P.C.B Layout (LX700 Connectors)

P5

GS8

A8

A5

AP3/A3

A7

G4

AP4/A4

P6

CN501

P3

CN1

A6

A9

To

Panel

CCFLTs

11

P.C.B Layout (LX700 LVDS Connector)

Remove the 4 Screws and the metal

plate to expose the LVDS Connector.

A2

LVDS Connector

A2

LVDS Connector

12

TC-32LX700 Board Description

Board Description Part Number

A-Board

AP-Board DC-DC, Power Switch DT-Board Digital Tuner (Exchange Only) G-Board Video 3, Headphone Jack GS-Board SD Card Slot V-Board Remote Receiver, LED P-Board Power (AC/DC) (Exchange Only) Control Panel

ASSY

Main (Rear Terminal, AV Switch, MCU, Audio & Video Processor, LVDS) (Exchange Only)

Control Button (Non-Serviceable, Control Panel Assembly should be exchanged for service.)

TNPH0683S

TNPA4155ABS TNAG172S TNPA4266S TNPA4206S TNPA4152ADS TZRXN010MRR K0RB00600004

13

Differences from Current models

LX600 LX60

A

VCTP

AUDIO

SWITCH

HDMI

(CEC)

Differences from LX600/60:

FPGA

DT

ATSC

Peaks Lite

A

AUDIO

SWITCH

VIDEO

SWITCH

LX700 LX70

Peaks Lite2

HDMI

(CEC)

HQ1L(*)

DT

* 32LX700 only

LVDS TX(*)

ATSC

1. Peaks Lite2 and VIDEO SW are introduced instead of VCTP, FPGA and Peaks Lite .

2. For LX700, HQ1L and LVDS TX are introduced for Motion Picture Pro.

3. HQ1L and LVDS TX are used to convert the picture frames from 60 to 120. This process helps to reduce after-images.

4. The DT board of the 32LX700 provides Channel Data output only. The MPEG2 and AC3 (Peaks Lite2) decoders are now part of the A board.

14

P Board ––

P Board

Main Power Board

T801

D821

15

P Board ––

P Board

When AC is applied to the TV, the Standby circuit of the P board outputs 5Vdc to the AP board. The STB5V passes through the AP board and enters the A board. On the A board The STB5V is converted to 3.3V to power the system control circuit for standby operation. The STB3.3V is also applied to the Remote Control receiver and the power LED on the V board. The MPU (IC1100) of the A board outputs the SUB_ON command to provide a ground connection to relay RL802 of the power supply board. On the AP board, the SUB_ON command is used to turn on a circuit (not shown in the diagram) that provides STB5V to relay RL802 via pin 15 of connector AP2/P2. When the relay is closed, DC voltage from the rectifier, approximately 105Vdc, is supplied to the LCD panel for conversion into 24Vdc. The output of the 24V generator passes through the P board and enters the AP board for conversion into SUB_5V, DTV9V (SUB_9V), and HQ3.3V.

If the power button (main unit or remote control) is not pressed within 25 seconds after applying AC to the unit, the SUB_ON command goes low to disengage the power relay. When the power button is pressed, the SUB_ON command goes high to repeat the same operation. The voltages remain present until the unit is turned off.

When the unit is turned on, the LCD panel’s inverter circuit uses the 24Vdc source to generate the 120Vac to illuminate the CCFLTs. The INV_ON command and the 12Vdc source enter the panel’s drive circuit via the connector AP2/P2 and P5 of the P board. The inverter circuit is monitored for abnormality. When a defect is detected, a SOS (High) output is provided to the A board MPU (IC1100) via Connectors P5 and P2/AP2.

Main Power Board

Caution: The P board is not to be repaired by you. It is to be exchanged only.

16

Main MPU (Power On Commands)

17

Main MPU (Power On Commands)

The STB 5V output of the P board passes through the AP board and enters the A board when the unit is plugged into the AC outlet. IC5702 of the A board converts the STB 5V to 3.3V to power the system control circuit. Activation of the power switch causes transistor Q5712 to turn off and output STB 3.3V to pin 18 of the MPU. Upon receiving the STB 3.3V, the MPU (IC1100) outputs the TV-SUB-ON command via pin 8 of connector A4/AP4. The TVSUB_ON command is routed to the P board to provide a ground connection for relay RL802 of the power supply board. On the AP board, The TV_SUB_ON command is used to turn on a circuit (not shown in the diagram) on the A board that provides STB_5V to relay RL802. As a result , the switch of relay RL802 on the P board closes to allow the output of 105Vdc to the LCD panel. The TV_Main_ON signal issued by IC1100 appears on pin 6 of connector AP4/A4 to enable the output of the sound+12V DC/DC converter. Pin 105 of IC1100 outputs the PANEL VCC command to the AP board to turn on the 12V DC/DC converter. The 12V output is provided to the panel via the P board.

Caution: Measure the 105Vdc source between pin 1 and 3 of connector P3. Hot ground must be used.

18

Standby Operation

19

Standby Operation

When the main power switch is activated, it is sensed on the A board by the MPU IC1100. The TV_SUB_ON signal is subsequently issued in response on pin 8 of connector A4/AP4. It turns on the transistors Q7224 and Q7223 to output the “Relay voltage on pin 15 of connector AP2/P2. The TV Sub_On signal is also provided to the relay via the resistor R7208 and pin 17 of connector AP2/P2. This pulls the contacts of the AC relay on the P board. The AC input is rectified and provided to the LCD panel for conversion into 24Vdc. The 24V is then provided to the inverter circuit of the LCD panel to produce the 120Vac that powers the backlight CCFLTs. The same 24V passes through the P board and enters the AP board for conversion into other voltages.

The over-voltage protection circuitry affiliated with each of the regulators located on the AP board monitors for over-voltage conditions. It is designed to turn off the AC power by disabling the SUB_ON command that turns on the AC relay.

When an over-voltage condition is detected on the AP board, the voltage at the base of transistor Q 7207 goes “high” to turn on Q7207, Q7206, Q7205, and Q7204. The TV_SUB_ON voltage at pin 17 of connector A2/AP2 is now grounded through Q7204 and the unit shuts down. To turn the unit back on, disconnect and reconnect the AC cord before pressing the power button.

20

SUB Voltages and Over--

SUB Voltages and Over

voltage Protection

The AP Board is responsible for the regulation, distribution and dissemination of all secondary voltages derived from the 24V output of the P Board. During standby operation, the 24V output of the P board biases the transistor Q7208 into operation, causing its collector to become “low”. The low at the collector of Q7208 causes the transistors Q7226, Q7227, and Q7450 to turn off. As a result, IC7205, IC7209, and IC7233 go into operation to immediately provide the Sub_5V, DT9V, BT30V, and HQ 3.3V output. The over-voltage protection circuitry affiliated with each of the regulators monitors for excessive current and overvoltage conditions. It is designed to turn off the AC power by disabling the SUB_ON signal needed to turn on the AC relay.

21

Main Voltages and Over--

Main Voltages and Over

voltage Protection

When the unit is turned on, the TV_Main_On command (high) of IC1100 biases the transistor Q7212 into operation, causing its collector to go “low”. The low at the collector of Q7212 causes the transistor Q7225 to turn off. As a result, IC7215 goes into operation to provide the Sound_15V output.

When the Panel_VCC_On command is issued, transistor Q7702 turns on causing Q7701 to turn off. Consequently, IC7212 turns on and outputs 12V. This voltage enters the A board via the connector AP4/A4. It is also provided to the LCD panel via the connector AP2/A2, the P board, and the connector P5 (not shown in the diagram).

The over-voltage protection circuitry affiliated with each of the regulators monitors for excessive current and over-voltage conditions. It is designed to turn off the AC power by disabling the SUB_ON signal needed to turn on the AC relay.

22

Inverter_On Command and Protection

The INV_ON/OFF command (high) of the MPU, IC1100 of the A board, passes through the AP and P boards before entering the LCD panel. On the LCD panel, it triggers the operation of the inverter to produce the 120V AC that powers the backlight CCFLTs. To avoid catastrophic failures, when the Panel_VCC_ON pin of the MPU goes “low”, Q7805 turns off. Consequently, Q7806 turns on to disable the operation of the inverter.

23

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Video Process Block Diagram

25

Video Process Block Diagram

The main function of the A board is to select and process one of the incoming video signals. Video inputs, component video Input, and the composite video output of the tuner are all connected to IC3001 for selection. The video output signal of the switch can be in any of the three formats: Video, Y/C, or Y, Pb, Pr. The selected output enters IC4510, the HDMI IF Receiver/Decoder IC, for A/D conversion. The comb filter inside IC4510 converts the composite video signal of the main picture to Y and C (luminance and chrominance) signals. S-Video, which is already Y/C separated, simply passes through the comb filter. The chrominance data is then applied to the Chroma Demodulator circuit to separate the color signal into Pb and Pr data. At the completion of this process , the format of the composite or S-Video signal is now the same as a digital 480i component signal. If the incoming video is in the 480p, 720P, or 1080i format, the Y, Pb, and Pr signals undergo A/D (analog to digital) conversion only. The 10 bit YUV data is provided to a video switch. The HDMI receiver section of IC4510 converts the incoming HDMI signals to a YUV video signal. The Video interface circuit selects between the two HDMI sources and outputs the YUV signal to the switch. The output of the switch is provided to the PEAKS LITE IC, IC8001.

Digital television reception of the tuner is output in the form of a transport stream (CHODATA). The transport stream enters the DTV I/F (Interface) section of IC8001 where the video signal is extracted and converted to YUV data. The output is provided to the Video Input switch for selection. The JPEG data of the GS board enters the JPEG I/F section of IC8001 for conversion into YUV data and output to the video switch. The video switch outputs the selected picture data to the Video Process circuit.

The Video Process section of the IC performs all picture control operations such as brightness, contrast, color, tint, etc. The output signal is then applied to the HQ1L circuit (IC4200) for frame doubling operation. IC4200 is the circuit responsible for the Motion Picture Pro operation that reduces afterimage by 50%. On Screen Display data such as channel numbers, Digital TV closed caption, and picture adjustments are mixed with the video data. The output of IC4200 is provided to the LVDS transmitter (IC4207). The transmitter distributes signals with low-jitter, while creating little noise. It reduces power consumption and the generated noise from data transmission. Another benefit of the LVDS standard is minimal concern for cable length.

The main MCU (IC1100) controls the entire operation of the A board. It serves as the controller that monitors all operations of the TV section (not display) of the unit. When watching digital television or viewing pictures from an SD card, the video process section of IC8001 converts the digital video into analog composite video signal for output at the monitor out jack.

26

Audio Process Block Diagram

27

Audio Process Block Diagram

IC3101 of the A board handles the audio selection of most inputs. Analog audio of the tuner and audio signals from composite, component, and DVI inputs are connected to IC3101 for selection. The output of IC3101 enters IC2106 and undergoes analog to digital conversion. The serial data output is provided to the audio DSP (Digital Signal Processor). Volume, bass, treble, and balance adjustments of the audio signal are performed by this circuit. The output is two channel PWM data that are applied to IC2301 and IC2302 for amplification. The PWM output signals of the power amplifiers are output to the right and left channel speakers for sound reproduction. The HDMI receiver section of IC4510 converts the incoming HDMI audio into serial data. The Audio interface circuit selects between the two HDMI audio and outputs the SD (serial Data) to the switch located inside IC2106. Two outputs are provided, one for the digital audio output jack, the other for the speakers. Digital television reception of the tuner is output in the form of a transport stream that contains MPEG2 video and AC3 audio. The transport stream enters the DTV I/F section of IC8001 where the audio signal is extracted and converted to serial data. Two outputs are provided to IC2106. One output consists of the AC3 audio that will be provided to the digital audio output jack. The other output consists of left and right audio that will be used to drive the speakers. Speaker output of the DTV and HDMI audio is selected and converted to analog. The analog audio is then output to an audio amplifier (IC2011) and then applied to the audio selector (IC3101). The optical jack audio signal is also selected and processed inside IC2106. Q2303 is a muting transistor that applies a low to IC2106 when a headphone jack is connected to the unit. Q2302 applies a low to IC2106 when the mute function of the unit is active.

28

MPU SOS Inputs and Blink Codes

29

MPU SOS Inputs and Blink Codes

One Blink: One blink of the power LED indicates a problem in the inverter circuit located on the LCD panel. The inverter board is not to be repaired in the field. Therefore a replacement is required.

Three Blinks: Three blinks of the power LED indicates an over-current or over-voltage condition in one of the DC supplies of the AP board. The AP board is repairable. Therefore the use of an ohmmeter and peak-hold-voltmeter is required to determine the cause of the shutdown. An over-voltage condition is definitely a defect of the AP board. An over-current condition may be due to a short circuit located in the AP board, A board, or the LCD panel.

Five, Seven, or Eight Blinks: The A board is responsible for five, seven or eight blinks of the power LED. The MAIN +3.3V, MAIN +5V, and MAIN +9V sources are all produced on the A board. The detection input pins of the MPU, IC1100, monitor for their presence.

Four or Six Blinks: The AP board is responsible for four or six blinks of the power LED. The DTV9V, and SUB_5V sources are produced on the AP board. The MPU IC1100 monitors for their presence when the unit is connected to AC

Power. A short or open circuit on the A board may also be responsible for their absence. Nine Blinks: Nine blinks of the power LED is due a short circuit in the audio output circuit (s) of the unit. The audio output

circuit is located on the A board. Confirm the status of the speakers. If defective, perform a replacement. If ok, replace the A board.

Ten Blinks: Ten blinks of the power LED indicates a malfunction of IC4200, the frame converter. This IC resides on the A board. Therefore ten blinks of the power LED requires the replacement of the A board.

30

Over--

Over

Current Protection Circuit

31

Over--

Over

BT30V, and the Panel VCC sources. If any of these voltage sources goes low, Q7210 turns on. As a result, the collector of Q7210 goes high to signal a shutdown condition to IC1100 on the A board. The T V_SUB_ ON pin of IC4002 goes low to deactivate the AC relay on the P board.

causing its collector to become “low”. The low at the collector of Q7208 causes the transistors Q7450 to turn off. As a result, IC7233 goes into conduction to immediately provide the HQ 3.3V output. When the 24 drops below the reverse breakdown voltage of D7206, transistor Q7208 turns off and transistor Q7450 turns on. IC7233 ceases to operate causing Q7451 to turn off and Q7452 to turn on. Consequently, the SUV_9V line is now grounded. Diode D7220 becomes forward biased and Q7210 outputs a high to trigger the shutdown of the unit.

Current Protection Circuit

The protection shutdown circuit is designed to monitor for a short or loss of the SUB_9V, SOUND_VCC,

During standby operation, the 24 volt output of the P board biases the transistor Q7208 into conduction,

32

Over--

Over

Current Protection Circuit 2

33

Over--

Over

Sound_VCC Protection

causing its collector to become low. The low at the collector of Q7208 causes the transistor Q7214 to turn off. When the PANEL_MAIN_ON command (high) is issued Q7212 turns on. Consequently Q7225 turns off, and IC7215 goes into conduction to provide the SOUND_15V output.

ground the PANEL_MAIN_ON voltage. Q7212 turns off and Q7225 turns on. IC7215 ceases to operate and the Sound_VCC is no longer output.

and R7492 receives 12V. Due to this condition, the transistor Q7210 remains off. If the SOUND_15V line becomes shorted, diode D7469 goes into conduction to turn Q7210 on. Consequently Q7210 outputs a high to shut down the unit.

Panel_VCC Protection

causing its collector to become low. The low at the collector of Q7208 causes the transistor Q7508 to turn off. When the PANEL_VCC_ON command (high) is issued, Q7702 turns on. Consequently Q7701 turns off, and IC7212 goes into conduction to provide the PANEL_12V output.

ground the PANEL_VCC_ON voltage. Q7702 turns off, and Q7701 turns on. IC7212 ceases to operate and the Panel_VCC is no longer output.

and R7488 receives 12V. Due to this condition, the transistor Q7210 remains off. If the Panel_12V line becomes shorted, diode D7472 goes into conduction to turn Q7210 on. Consequently Q7210 outputs a high to shut down the unit.

operation, causing its collector to become “low”. The low at the collector of Q7212 causes the transistors Q7225 to turn off. As a result, IC7215 goes into operation to provide the Sound_15V output.

Current Protection Circuit 2

During normal operation, the 24 volt output of the P board biases the transistor Q7208 into conduction,

When the 24 drops below the reverse breakdown voltage of D7206, Q7208 turns off, Q7214 turns on to

During normal operation, the anode of D7469 receives 5V and the junction of D7469, D7470, R7486,

During normal operation, the 24 volt output of the P board biases the transistor Q7208 into conduction,

When the 24 drops below the reverse breakdown voltage of D7206, Q7208 turns off, Q7508 turns on to

During normal operation, the anode of D7472 receives 5V and the junction of D7472, D7473, R7493,

When the unit is turned on, the TV_Main_On command (high) of IC1100 biases the transistor Q7212 into

34

Power LED Timing Table

35

Power LED Timing Table

36

Self-Check and Reset Function

Self-Check Function:

1. Checks the communication IIC bus lines

2. Provides a SOS History To Access the Self-Check Mode: Turn the TV on and select an

To Access the Self-Check Mode

active channel. While pressing the “VOLUME ( - )” button on the main

unit, press the “OK” button on the remote control for more than 3

seconds.

This procedure is useful to display the unit’s firmware version and check IC data communications.

To Reset the unit: Turn the TV on and select an active channel.

: Turn the TV on and select an

While pressing the “VOLUME ( - )” button on the main unit, press the

“Menu” button on the remote control for more than 3 seconds.

The Reset function clears channel programmed settings, picture settings, channel labels, LOCK mode settings, and password.

It restores the unit to factory shipping settings.

To Exit the Self-Check Mode, Disconnect the AC cord from the wall outlet.

37

Self-Check Menu

SELF CHECK ----.XXXXXX-XXXXXX

DT OK HQ1L OK ADV OK VSW OK ADAV OK ASW OK TUN1 OK TUN2 OK FE OK GenX4 OK

MEM1 OK MEM2 OK

38

Check Point

A-Board

39

Serviceman Mode

To enter the Serviceman Mode, turn the TV on and while

pressing the “VOLUME ( - )” button on the main unit, press the

“RECALL” button of the remote control three times within 3 seconds.

To exit the Serviceman Mode, Press the Power button on the

TV or the Remote Control.

40

Serviceman Mode Menu and Navigation

SERVICE ADJUST WB-ADJ 0PTION RM-SET SRV-TOOL

Peaks Soft 0.270 Peaks EEP 1.00 LSI DATA 0.00.36 GenX SOFT 0.23.00 GenX EEP 0.40.00 GenX COR 0.00.00 HQ1L EEP 15

Key command

“1” button...Main items Selection in forward direction “2” button...Main items Selection in reverse direction “3” button...Sub items Selection in forward direction

NOTE: This is not part of the

Menu.

“4” button...Sub items Selection in reverse direction “VOL” button...Value of sub items change in forward direction ( + ), in reverse direction ( - )

41

Adjustment Data

MAIN ITEM

SUB ITEM

ADJUST CONTRAST

0000

DATA

YMAX

“1” or “2” button of the remote control to select the main Adj. item “3” or “4” button of the remote control to select the sub Adj. Item

“Vol. (-)” or” Vol. (+)” to change the data

Note: Record the original data on a sheet of paper prior to making any adjustment.

42

SRV-TOOL

TD2Microcode: 81c0000e Flash ROM: 1- 227E PCTC: 00 . 00 . 00 . 00 . 00 Time 000040:40 Count 0000049

To access:

1. Select “SRV-TOOL” in the Serviceman Mode menu.

2. Press the [OK] button on the remote control.

43

SRV-TOOL

Display of SOS History

SOS History

(Number of LED blinking) indication. From the left side; Last SOS, before Last, third occurrence before last, 2 indication will be cleared by entering the “Self-check mode. The unit will be forced to factory shipment setting”.

POWER ON TIME/COUNT

Time: Cumulative power on time, indicated in decimal numbers__ hour: minute

nd

occurrence after shipment, 1

st

occurrence after shipment. This

Count: Number of power on/off times in decimal numbers This indication will not be cleared by self-check or any command.

Exit:

Disconnect the AC cord from wall outlet.

44

Voltage Chart of AP-board

AP-board

VOLTAGE TEST POINT SPECIFICATION CONNECTOR

24V TP7904 24.0 ± 1.2V AP2 _PIN 1, 2, 3 SUB_5V TP7211 5.12 ± 0.25V AP3_PIN 21, 22 SUB_9V TP7213 9.27 ± 0.45V AP3_PIN 8, 17, 18

BT_30V TP7601 31.5 ± 2.5V AP3_PIN 7

HQ_3.3V TP745 3.38 ± 0.17 A-Board

SOUND_15V TP7209 15.2V ± 0.75V AP3_PIN 2, 3

PANEL_12V TP7702 12.14 ± 0.6V AP4_PIN 11, 12

STB_5V TP7151 5.0 ± 0.5V AP4_PIN 3

45

Voltage Chart of P and A boards

P-board

VOLTAGE TEST POINT SPECIFICATION

STB_5V TP823 5.0 ± 0.5V

A-board

VOLTAGE TEST POINT SPECIFICATION

STB3.3V TP7006 3.3 ± 0.16V SUB1.2V TP5601 1.26 ± 0.06V SUB1.8V TP5602 1.83 ± 0.09V SUB3.3V TP5600 3.3 ± 0.16V

MHQ1.2V TP4209 1.22 ± 0.06V

MHQDDR2.5V TP4210 2.5 ± 0.12V

46

Voltage Chart of DT board

A-board

VOLTAGE TEST POINT

A- BOARD

SUB_3.3V TP8332 3.3 ± 0.16V SUB_1.2V TP8328 1.26 ± 0.06V

SUB_5V TP8326 5.12 ± 0.25V

30V_A TP8331 31.5 ± 2.5V

DT-board

SPECIFICATION

47

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Troubleshooting Signal Problems

We can classify the signal problem into three categories. It is important to check all functions to determine whether both picture and sound problem exist. Checking all functions helps us determine whether the cause of the problem is the panel, the video processor or sound processor.

Picture NG and Sound OK

1) Picture OK and Sound NG

2)

Picture NG and Sound NG

3)

49

Picture

NG

and Sound

OK (LX700/LX70 )

Is there a

picture from any

of the inputs?

No

No picture but is there OSD?

Yes

A Board

Yes

No

No picture from

the AV Terminal

No Picture

from Analog TV

No Picture from

Digital TV

No Picture from

HDMI Input

LCD Panel or A board

A Board

a picture from the

A Board

Is there

No

A Board

AV Terminals?

Yes

See slide “No Picture from TV Reception”

HDMI I/F

A

HDMI

DT

TU8300

TUNE

R

AV1

AV2

COMPONENT

Monitor Out

G

AV3

1

2

IC8302

FRON

END

PROCES S

A/D

IC3001

T

VIDEO

SWITCH

IC4510

ＳＷ

50

IC4200

HQ1L

IC8001

Peaks Lite2

ＳＣＡＬＩＮＧ/

ＩＰＣＯＮＶＥＲＴＥＲ/

PICTURE CORRECT/ OSD

VIDEO PROCESS

DTV

IC4207

LVDS TX

LVDS

IC1100

STB

MCU

Analog Digital

LCD

Panel

GS

LX700 Only

Picture OK and

Sound NG

(LX700/LX70)

Is there

sound from any of the

input sources?

No

Is there sound

from the

headphone?

Yes

A Board

No

Yes

from any of the AV

from analog TV

No sound

from Digital TV?

No Sound

from HDMI Input

of the AP board. Refer to

Slide 43 for test point

No sound

terminals.

No sound

Is there 15V

on connector AP3

locations

Yes

A Board or Speaker

A Board

Is sound

from any of the AV Terminals

OK?

Yes

DT Board

Is sound

from any of the AV Terminals

OK?

Yes

A

DT Board

HDMI1

HDMI2

A Board

DT

TU8300

TUNER

IC830 2

No

AV1

AP Board

AV2

COMPONEN

T

MONITOR OUT

AV3

G

HEADPHONE

FRON

T

END

No

L/R

IC451 0

HDMI I/F

IC3101

AUDIO

SWITCH

HP AMP

A Board

No

A Board

IC2106 Audio DSP

IC8001

Peaks Lite2

AUDIO

PROCESS

DTV

IC2301

AUDIO

AMP

IC2302

AUDIO

AMP

IC1100

STB

MCU

Analog Digital

LX700 Only

51

Picture NG

and

Sound NG

(LX700/LX70 )

Input Source

check

Analog TV

Picture NG

Sound NG

AV Terminal

Picture NG

Sound NG

HDMI Input

Picture NG

Sound NG

Digital TV

Picture NG

Sound NG

AV Terminal

Picture &

Sound OK?

Yes

DT Board

A Board

AV Terminal

Picture &

Sound OK?

Yes

No

A Board

: Line where problem might occur

IC4510

IC451 0

HDMI I/F

L/R

A/D

IC3001

VIDEO

SWITCH

IC3101

HDMI I/F

ＳＷ

IC4200

HQ1L

ＩＰＣＯＮＶＥＲＴＥＲ/

PICTURE CORRECT/ OSD

VIDEO PROCESS

DTV

IC2106 Audio DSP

IC4207

LVDS TX

IC8001

ＳＣＡＬＩＮＧ/

IC2301

AUDIO

AMP

IC2302

AUDIO

AMP

LVDS

IC1100

STB

MCU

A

HDMI1

HDMI

2

DT

TU8300

TUNE

R

AV1 GS AV2 COMPONENT

Monitor Out

G

A

DT

TU8300

TUNER

AV3

HDMI1

HDMI2

IC830 2

TU8302 FRON

T

END

FRON

T

END

PROCES S

Analog Digital

LCD

Panel

LX700 Only

Analog Digital

DT Board

52

AV1

AV2

COMPONEN

T

MONITOR OUT

AV3

G

HEADPHONE

L/R

AUDIO

SWITCH

HP AMP

IC8001

Peaks Lite2

DTV

AUDIO

PROCESS

IC1100

STB

MCU

LX700 Only

No Picture from TV Reception

Is there video from

any of the inputs?

Yes

Check for the BT30V, DTV_9V, and

SUB_5V on connector AP3

of the AP board. Refer to Slide 45 for test

point locations.

No

See the

troubleshooting

flowchart for No

picture.

Yes

Are SUB_3.3V

and SUB_1.2V present

on the A board? Refer to

Slide 46 for test

point locations.

Yes

Replace the DT board

Are DTV 9V

And SUB

5V OK?

Yes

No

Replace the A board

Replace defective Regulator and biasing components. Reference the power distribution diagram on Slide 21.

Is the BT30V source

OK?

53

No

Check the cathode of D7601 on the AP Board. Cathode of D7601 should measure 30V. If not, repair the DTV9V DC/DC converter.

No Picture

Is there picture from

any of the inputs?

Yes

Check for the BT30V, DTV_9V, and

SUB_5V on connector AP3

of the AP board. Refer to Slide 45 for test

point locations.

No

See the

troubleshooting

flowchart for No

picture.

Yes

Are SUB_3.3V SUB_1.2V

OK?

Yes

Replace the DT board

Are DTV 9V

And SUB

5V OK?

No

Replace the A board

Yes

No

Is the BT30V source

OK?

Replace defective Regulator and biasing components. Reference the power distribution diagram on Slide 21.

54

Check the cathode of D7601 on the AP Board. Cathode of D7601 should measure 30V. If not, repair the DTV9V DC/DC converter.

No Video, Dark Blue Screen

Try using a different video input source.

Try the Tuner, Component, S-Video or

HDMI input.

Does any

input

work?

No

Yes

Check the video input connections and

termination points for a possible cold

solder joint or connection problem.

Replace defective Regulator and biasing components. Refer the power distribution diagram on Slide

21.

Check for the BT 30V, SUB 9V, &,

SUB5V sources on connector AP3

of the AP board. Refer to Slide 45 for test

point locations.

No

BT30V, SUB9V SUB5V

OK?

Yes

Continued on next

page

Did this

fix the

problem?

No

Replace the A Board.

Yes

Problem Solved

55

No Video, Dark Blue Screen (Continued)

From the last page

Remove the metal plate

From where it sits on the A board in order to

access the LVDS connector. There are four

screws that need to be removed. See slide 12.

Confirm the connection of the

LVDS Connector (CN A2).

Is the picture

restored?

No

Replace the A board.

56

Yes

Problem Solved

No Audio

Problem

Solved

A Board

Determine which audio input is defective. Check for poor solder connections in the vicinity of the

audio connection in question.

Yes

Is the Audio

ok?

Try using a different audio input

source. Try the Tuner, Component,

S Video or HDMI input.

Yes

Are other

Audio inputs

OK ?

Check the L/R speaker output

connection.

Reseat connector A5 and A6.

Does this fix

the Audio

problem?

No

Yes

Problem

Solved

No

Change the A board.

Is there 15V on

pins 2 & 3 of

connector

AP3/A3?

Yes

Change the A Board.

57

No

Check regulator IC7215 and biasing component on the AP Board. Replace if defective.

No Power

Refer to the AP Board test points

Slide 45.

Turn on the Main

Power Switch.

Yes

Is there

105Vdc between pins 1

and 3 of CN P3?

No

Replace the

P Board.

Is there

24Vdc at pin 1

of CN P6?

No

Replace the LCD

Panel.

Check for 4.5V on pin 15

of connector AP2 (RELAY.)

4.5V

Present?

No

The Main_SW_Detect signal

on Pin 7 of connector AP4

should go low when the Main

Power switch is depressed.

No

Pin 7

low?

Yes

See Next Page.

Yes

Replace the

AP board.

Can an audible

click be heard

from the Power

relay?

No

Standby 5V

On Pin 3 of CN

A4 OK?

No

Check for STBY 5V on pin 16 of

connector AP2.

5V

Present?

No

If connector is good, replace

the P Board.

Yes

Note: the Power

LED should blink.

58

No Power

From Last Page.

Make sure connector A4 of the A

board is seated properly. Unit will

exhibit this condition if the connector

is unplugged.

Does the unit

come on?

Yes

Problem solved

No

Replace the A board.

59

Power LED Blinks One Time (INV_SOS)

Power LED blinks once

Is connector

P5 properly

seated?

Yes

Does

pin 4 of CN P5

go high before

shutdown?

Yes

No

Connect connector P5.

Turn the unit on.

Does the unit

Power up?

Change the A board.

Yes

Problem solved

Replace the LCD panel.

60

Power LED Blinks Three Times (TV_SOS)

Conduct a voltage

check on the AP Board

right before shutdown.

Does pin 1 of CN A4/ AP4 go

high?

No

Replace the A board

Yes

Is there

24V at Pin 1

of CN P6?

Yes

Does the

cathode of

D7208 go low?

No

Does the

cathode of

D7220 go low?

No

Does the

cathode of

D7469 go low?

No

Yes

Is there

105Vdc between

pins 1 and 3 of CN

P3?

Yes

Check and replace if necessary IC7209,

its biasing components and load.

Check and replace if necessary IC7209,

its biasing components and load. Perform

the same procedure for IC7233.

Check and replace if necessary IC7215,

its biasing components and load.

No

Replace the P board.

Replace the LCD Panel.

No

Does the

cathode of

D7472 go low?

No

Yes

Check and replace if necessary IC7212,

its biasing components and load.

61

Power LED Blinks Four Times

Confirm the connection of CN AP3, P3, and P6.

Are

the connectors

properly seated?

Is there

24V at Pin 1

of CN P6?

Yes

Is DTV9V and

SUB_5V present on the

AP board? Refer to slide

? for test point.

No

Reseat the connectors.

unit on. Does the unit

No

pins 1 and 3 of CN

No

Replace the AP board.

Turn the

Power up?

Is there

105Vdc between

P3?

Yes

Conduct all voltage

checks before

shutdown.

Yes

Problem solved

No

Replace the P board.

Replace the LCD Panel.

Yes

Replace the A board.

62

2008 LCD Television Models

Technical Guide

TC-37LZ85U/TC32LX85 LCD Display Television

63

Full HD TC-LZ85 & HD TC-LX85 Series

VIERA Technology for Ultimate Full-HD Picture Quality

•178° Wide Viewing Angle with IPS Alpha Panel

•10,000:1 High Contrast with Intelligent Scene Controller

•x.v.Color

•Deep Color (HDMI™ 1.3)

Other Features For Comfortable TVs Life

•Built-in SD Memory Card Slot with HD Photo Viewer

•Gallery Player

•VIERA Link™

•PC Input

•Horizontal Arch Design

®

read

×3

64

37

TC-37LZ85

37” Class LCD HDTV

(Measured Diagonally)

Chassis structure (37 Full HD type)

New

2007 Model (ex 37LZ700D) 2008 Model (ex 37LZ85 )

I

nv

e

r

t

e

r

Notice

A

P

LCD Panel

P

LCD Panel

A

P

H

D

G

I

nv

V

I

nv

e

r

t

e

r

e

r

t

e

r

H and DG boards are integrated to A board

V

I

nv

e

r

t

e

r

The H and DG board are integrated to A board of the 2008 model.

Therefore the Input switch, system control, and signal processing are performed by the A board.

The AP board is merged with the P board.

65

Chassis structure (37 HD type)

New

2007 Model (ex 32LX70 series)

A

P

I

nv

V

e

r

t

e

r

I

nv

A

e

r

t

e

r

Notice

2008 Model (ex 32LX85 series)

LCD PanelLCD Panel

A

P

V

I

nv

e

r

t

e

r

I

nv

e

r

t

e

r

AP board is now merged with the P board

The A, P, and V boards are the only printed circuit boards used in the 2008 models.

66

Signal Circuit Block Diagram

The A board is responsible for video input selection, video processing, and audio processing. The LVDS output signal is provided to the LCD panel for display and the audio signal to the speakers, headphone jack, and optical output jack.

67

TC--

TC

32LX85 / TC37LZ85 Signal Circuit Block Diagram

The A board is responsible for video input selection, video processing, and audio processing. The LVDS output signal is provided to the LCD panel for display and the audio signal to the speakers, headphone jack, and optical output jack.

68

TC37LZ85 Signal Circuit Block Diagram

69

TC37LZ85 Signal Circuit Block Diagram

The main function of the A board is to select and process incoming video signals. Video inputs, Component Video Input, and the composite video output of the tuner are all connected to IC3301 for selection. The video output signal of the switch can be in any of the three analog formats: Video, Y/C, or Y, Pb, Pr. The selected output enters IC4510, the HDMI IF Receiver/Decoder IC, for A/D conversion. The 10 bit YUV data is provided to a video switch. The HDMI receiver section of IC4510 converts the incoming HDMI signals to YUV data and outputs to the switch. The output of the switch is provided to the PEAKS LITE IC, IC8001.

Digital television reception of the tuner is output in the form of a transport stream (CHODATA). The transport stream enters the DTV I/F (Interface) section of IC8001 where the video signal is extracted and converted to YUV data. The JPEG data of the GS board enters the JPEG I/F section of IC8001 for conversion into YUV data. The internal video selector of IC8001 (not shown in the diagram) selects and outputs the desired picture data to the Video Process circuit.

The Video Process section of the IC8001 performs all picture control operations such as brightness, contrast, color, tint, etc. On Screen Display data such as channel numbers, Digital TV closed caption, and picture adjustments are mixed with the video data. The output of IC8001 is provided to IC4202, the LVDS transmitter. The transmitter distributes signals with low-jitter, while creating little noise. It reduces power consumption and the generated noise from data transmission. Another benefit of the LVDS standard is minimal concern for cable length. The output of the LVDS transmitter is provided to the LCD for display.

70

TC32LX85 Signal Circuit Block Diagram

71

TC32LX85 Signal Circuit Block Diagram

The main function of the A board is to select and process incoming video signals. The HDMI receiver located inside IC4003 converts the HDMI signal into YUV data. Analog signals such as; Video inputs, component video Input, composite video output of the tuner are all connected to IC4003 for selection. The selected analog signal enters the A/D converter circuit for conversion into YUV data. An internal switch of IC4003 selects the desired signal and outputs to the PEAKS LITE IC, IC8001.

Digital television reception of the tuner is output in the form of a transport stream (CHODATA). The transport stream enters the DTV decoder section of IC8001 where the video signal is extracted and converted to YUV data. The JPEG data of the GS board enters the SD/IF section of IC8001 for conversion into YUV data. The internal video selector of IC8001 (not shown in the diagram) selects and outputs the desired picture data to the Video Process circuit.

The Video Process section of the IC8001 performs all picture control operations such as brightness, contrast, color, tint, etc. On Screen Display data such as channel numbers, Digital TV closed caption, and picture adjustments are mixed with the video data. The RGB output of the video process section of the IC undergoes conversion to a LVDS signal before being output to the LCD panel for display.

72

TC37LZ85 Audio Circuit Block Diagram

73

TC37LZ85 Audio Circuit Block Diagram

IC3301 of the A board handles the audio selection of most inputs. Analog audio of the tuner and audio signals from composite, component, and DVI inputs are connected to IC3301 for selection. The output of IC3301 enters IC2106 and undergoes analog to digital conversion.

IC4510 converts the incoming HDMI audio into serial data and outputs to IC2106. Digital television reception of the tuner is output in the form of a transport stream that contains MPEG2 video and AC3 audio. The transport stream enters the DTV decoder section of IC8001 where the audio signal is extracted and converted to serial data. The DTV audio data is output to the audio DSP (Digital Signal Processor) IC2106 for processing.

The DSP IC2106 provides three audio outputs. One output is either AC3 or PWM audio connected to the digital audio output jack. A second output is analog audio provided to the headphone jack. The third output is adjusted for volume, bass, treble, and balance and then output as PWM data to the audio amplifier IC2301. The amplified two channel PWM data is output to the right and left channel speakers for sound reproduction.

74

TC32LX85 Audio Circuit Block Diagram

75

TC32LX85 Audio Circuit Block Diagram

IC4003 of the A board handles the audio process of all inputs. Analog audio of the tuner and audio signals from composite, component, and DVI inputs are connected to IC4003 for selection and process..

IC4503 converts the incoming HDMI audio into serial data and outputs to IC4003. Digital television reception of the tuner is output in the form of a transport stream that contains MPEG2 video and AC3 audio. The transport stream enters the DTV decoder section of IC8001 where the audio signal is extracted and converted to serial data. The DTV audio data is then output to IC4003 for processing.

IC4003 provides three audio outputs. One output is either AC3 or PWM audio connected to the digital audio output jack. A second output is analog audio provided to IC4002 for amplification and then the headphone jack. The third output is adjusted for volume, bass, treble, and balance and then output as PWM data to the audio amplifier IC2301. The amplified two channel PWM data is output to the right and left channel speakers for sound reproduction.

76

Power Supply Overview

77

TC--

TC

37LZ85 Power Supply Description

78

TC--

TC

37LZ85 Power Supply Description

When AC is applied to the TV, the Standby circuit of the P board outputs STB5V to the A board. On the A board The STB5V is converted to 3.3V to power the system control circuit (not shown in the diagram) for standby operation. The STB3.3V is also applied to the Remote Control receiver and the power LED on the V board. The MCU (IC1100) of the A board outputs the SUB_ON command to provide a ground connection to relay RL802 of the power supply board. On the A board, the SUB_ON command is used to turn on a switch that provides STB5V to relay RL802 via pin 13 of connector A04/P6. When the relay is closed, 370Vdc from the PFC (Power Factor Control) is supplied to the LCD panel for conversion into 120AC. The 370Vdc of the PFC is also provided to the switch mode power supply for conversion into Sub+9V, BT+30V, DTV+12V, SUB+5V.

If the power button (main unit or remote control) is not pressed within 15 seconds after applying AC to the unit, the SUB_ON command goes low to disengage the power relay. As a result, only STB+5V is output to power the system control circuit of the a board.

When the power button is pressed, the SUB_ON command goes high to repeat the same operation. The voltages remain present until the unit is turned off. The MCU also provides the Panel_ON command to trigger the output of PANEL+12V. This voltage is used to turn on the inverter PCBs for the production of 120VAC used to illuminate the backlights of the LCD panel. The PANEL+12V is also used to operate the drive circuits of the LCD panel. The MCU also outputs the Main_ON command to trigger the output of the SOUND+17V source.

When the power supply output is too high, an over-voltage detection circuit outputs a high to the A board to

trigger the shutdown of the unit. The power LED does not blink.

An over-current detection circuit on the power supply board monitors for short circuits. If a detection is made, a

high is output to IC1100 to shut down the unit and provide 3 blinks of the power LED.

Caution: The P board is to be exchanged only.

79

Self--

Self

Check and Reset Function

80

SOS and Power LED Indication

81

Power LED Blinks 1 Time

Pin 4 of connector P2 should toggle low after the backlights of the LCD panel turn on. If the backlights do not come on or pin 4 of CN P2 does not toggle low, Reseat the connectors A4, P6, and P2. Confirm the presence of 370Vdc at pin 1 of connector P5 and 12V at pin 1 of connector P2 before replacing the LCD panel.

82

Power LED Blinks 3 Times

Pin 10 of connector P7/A3 outputs a high when an over-current condition is detected. On the power supply board, locate the test points for the SUB9V, SOUND17V and BT30V. Using an ohmmeter, determine if there is a short between each of the test-point and ground. If a test-point is shorted, disconnect the connector P7 or A3 to isolate the short to either the A or P board.

83

Power LED Blinks 4 or 5 Times

The DTV12V and SUB9V lines are monitored by the MCU. If the voltage corresponding to the number of blinks is missing or shorted, the MCU shuts down the unit and blinks the Power LED. Reseat the connectors P7 and A3 and turn on the unit. If the shutdown persists, use a voltmeter to measure the voltage. If it is present, replace the A board. If it is absent, use an ohmmeter to determine if there is a short to ground. When a short is detected, disconnect the connector P7 or A3 to isolate the short to either the A or P board.

84

Power LED Blinks 6 or 7 Times

The SUB5V and SUB3.3V lines are monitored by the MCU. When the SUB5V is missing or shorted, the MCU shuts down the unit and blinks the Power LED. Reseat the connectors P7 and A3 and turn on the unit. If the shutdown persists, use a voltmeter to measure the voltage. If it is present, replace the A board. If it is absent, use an ohmmeter to determine if there is a short to ground. When a short is detected, disconnect the connector P7 or A3 to narrow it to the A or P board. A seven-blinks shutdown is always caused by the A board.

85

Power LED Blinks 8 or 9 Times

On the A board, the MCU (IC1100) monitors the SOUND+17V line and the operation of the audio power amplifier IC2301. If IC2301, or the 17V lines develops a short to ground, a high is provided to the MCU to trigger a SOS condition. The power LED blinks 9 times.

Use a voltmeter to measure the SOUND+17V source. If it is present, replace the A board. If it is absent, use an ohmmeter to determine if there is a short to ground. When a short is detected, disconnect the connector P7 or A3 to narrow it to the A or P board. A eight-blinks shutdown is always caused by the A board.

86

Power LED Blinks 1 Time (TC--

Power LED Blinks 1 Time (TC

32LX85)

Pin 5 of connector A16 should toggle low after the backlights of the LCD panel turn on. If the backlights do not come on or pin 5 of CN A16 does not toggle low, Reseat the connectors A3, P3, and P7. Confirm the presence of 24Vdc at pin 1 of connector P7 and 12V at pin 28 of connector A2 before replacing the LCD panel.

87

Power LED Blinks 3 Times (TC--

Power LED Blinks 3 Times (TC

32LX85)

Pin 10 of connector P3/A3 outputs a high when an over-current condition is detected. On the power supply board, locate the test points for the SUB9V, SOUND15V, BT30V, and PANEL12V. Using an ohmmeter, determine if there is a short between each of the test-point and ground. If a test-point is shorted, disconnect the connector P3 or A3 to isolate the short to either the A or P board.

88

Power LED Blinks 4 or 5 Times (TC--

Power LED Blinks 4 or 5 Times (TC

32LX85)

The DTV12V and SUB9V lines are monitored by the MCU. If the voltage corresponding to the number of blinks is missing or shorted, the MCU shuts down the unit and blinks the Power LED. Reseat the connectors P3 and A3 and turn on the unit. If the shutdown persists, use a voltmeter to measure the voltage. If it is present, replace the A board. If it is absent, use an ohmmeter to determine if there is a short to ground. When a short is detected, disconnect the connector P3 or A3 to isolate the short to either the A or P board.

89

Power LED Blinks 6 or 7 Times (TC--

Power LED Blinks 6 or 7 Times (TC

32LX85)

The SUB5V and SUB3.3V lines are monitored by the MCU. When the SUB5V is missing or shorted, the MCU shuts down the unit and blinks the Power LED. Reseat the connectors P7 and A3 and turn on the unit. If the shutdown persists, use a voltmeter to measure the voltage. If it is present, replace the A board. If it is absent, use an ohmmeter to determine if there is a short to ground. When a short is detected, disconnect the connector P7 or A3 to narrow it to the A or P board. A seven-blinks shutdown is always caused by the A board.

90

Power LED Blinks 8 or 9 Times (TC--

Power LED Blinks 8 or 9 Times (TC

32LX85)

On the A board, the MCU (IC4003) monitors the SOUND+17V line and the operation of the audio power amplifier IC2301. If IC2301, or the 15V lines develops a short to ground, a high is provided to the MCU to trigger a SOS condition. The power LED blinks 9 times.

Use a voltmeter to measure the SOUND+15V source. If it is present, replace the A board. If it is absent, use an ohmmeter to determine if there is a short to ground. When a short is detected, disconnect the connector P3 or A3 to narrow it to the A or P board. A eight-blinks shutdown is always caused by the A board.

91

Picture Defect (1)

Trouble

Where is

the abnormal picture

displayed ?

Upper or Lower

Left or Right

Vertical or Horizontal line

(1)Part of the screen

Upper

Panel

Lower

Panel

Right

Panel

Left

Panel

(2)All over the screen

All over the screen

(3)No picture

Many vertical lines

Non-uniformity color

92

Abnormal color

Panel

OSD trouble

A Board

Picture Defect (2)

<Symptom>Upper or Lower Defect

Abnormality means No Picture, Picture noise, abnormal picture, Full Horizontal line etc.

Panel Drive Panel Drive

Panel Drive

Symptom: Upper trouble

Ａ

Tuner

Input

Terminal

Signal

Processor

Panel (Panel drive) Relation to panel drive location, 1/3 or 2/3 area will be troubled.

LCD panel

93

Picture Defect (3)

<Symptom>Left or Right half defect

No Picture, Picture noise, Full Horizontal line, etc.

Panel Drive Panel Drive

Panel Drive

Symptom: Right half picture trouble

Ａ

Tuner

Input

Terminal

Signal

Processor

LCD panel

Panel (Panel drive) or A board

94

Picture Defect (4)

<Symptom>Horizontal line

Panel Drive Panel Drive

Panel Drive

Symptom: Horizontal line

Ａ

Tuner

Input

Terminal

Signal

Processor

LCD panel

Panel

95

Picture Defect (5)

<Symptom>Vertical line

Panel Drive Panel Drive

Panel Drive

Symptom: Thin vertical line

Ａ

Tuner

Input

Terminal

Signal

Processor

LCD panel

Panel

96

Picture Defect (6)

<Symptom>Vertical line noise

Panel Drive Panel Drive

Vertical noise

LCD panel

Panel Drive

Symptom: Vertical noise

Ａ

Tuner

Input Terminal

Signal Processor

Panel or A board

97

Picture Defect (7)

<Symptom>Sub picture NG

Symptom: Sub picture NG

Panel Drive Panel Drive

LCD panel

A board

Panel Drive

Ａ

Tuner

Input

Terminal

Signal

Processor

Note: There is not sub picture function on some models.

98

Picture Defect (8)

<Symptom>Non uniformity color

Panel Drive Panel Drive

Panel Drive

Symptom: Irregular color

Ａ

Tuner

Input

Terminal

Signal

Processor

LCD panel

Panel

99

Picture Defect (9)

<Symptom>Vertical lines all over screen

Panel Drive Panel Drive

Panel Drive

LCD panel

Tuner

Input

Terminal

Signal

Processor

Symptom: Vertical line all over screen

Ａ

Mainly A board, in some cases panel

100

Panasonic TC-32LX70, TC-32LX700, TC-37LZ85, TC-32LX85 Technical Guide

Specifications and Main Features

Frequently Asked Questions

User Manual