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LC-26D44E/S/RU-BK/GY

4 – 1

LC26D44E-BK

Service Manual

 

No power supply (Front LED does not light up) and no power-up even if turned on (Front LED light up).

Is the wire harness in the unit properly connected?

NO

Reconnect and recheck the wire harness.

 YES

Are F7100 and F7101 normal?

NO

Are L7100, L7102, VAR7100, X7100, BD7100, T7100, etc. faulty? 
Check if the peripheral circuits are short-circuited.

 YES

Is approx. 400V applied to both ends of C7100?

NO

Does the PFC circuit normally work?
(Check L7103, T7100, D7100, U7300, Q7305, etc. and the peripheral 
circuits.)

 YES

Is a voltage of BU5V applied to pin (11) of connector 
(CN7200)?
(Set the main power SW to OFF.)

NO

Does the SWITCHING circuit normally work?
(Check the primary side of T7101, U7101, Q7101, D7105, D7107, 
etc., the secondary side of D7290, L7290, Q7291, U7291, F7290, etc. 
and the peripheral circuits such as AC_DET circuit.)

 YES

Are 13V and S13V supplied when the power switch is 
turned on?

NO

Do D7260, Q7265, U7265, L7260, F7250, F7260, etc. normally work? 
(PS_ON_LINE, AC_DET_LINE, etc.)

 YES

Is 38V supplied when the power switch is turned on?

NO

Check the primary side of D7250, D7251, L7250, ZD7250, etc., the 
protection circuits of Q7250, ZD7250, ZD7251, etc. and the peripheral 
circuits.

LC-26D44E/S/RU-BK/GY

4 – 2

The backlight does not light

Are all fluorescent lamps on?

NO

Check each fluorescent lamp, and replace if defective.
(CN7501-9, etc.)

 

NO

Is 38V applied to both ends of C7500/C7501?

NO

Refer to "No power supply (Front LED does not light up)" and "No 
power-up even if turned on (Front LED light up)".

 YES

Is F7500 normal?

NO

Check if the  peripheral circuits are short-circuited or parts are faulty. 
(L7500, MOS7500-3, etc.)

 YES

Is IC12V supplied from the collector side of Q7501?

NO

Check if the STB_ON/OFF signal sent from PIN(2) of connector 
CN7502. (Q7501-2, Q7508, Q7510, etc.)

 YES

Is a voltage of 5V applied to PIN(5) of  IC7500?

NO

Does the regulator circuit normally work?
(Check Q7503, U7500, etc. and the peripheral circuits.)

 YES

Does each control signal of connector CN7502 normally 
function?

NO

Check each control circuit.

PIN(3) OFL1 (PWM light control signal input)

OFL (PWM light control signal input)/H: Lamp ON, L: Lamp OFF

PIN(5) ERR (Error output)

ERR (Error output)/H: Normal, L: Error

PIN(7) REG2 (Light control method identification)

REG2 Light control method identification)/H: External PWM input, L: 
Analog voltage input

 YES

Is [0] displayed as the number of [LAMP_ERROR] in the 
process mode?

NO

Reset the number of [LAMP_ERROR] to the default value in the pro-
cess mode?

 YES

Is the drive signal sent from PIN(19, 20)/(PDRV_A, 
NDRV_B and PIN(12, 11)/ (RDR_C, NDRV_D) of IC7500?

NO

Check IC7500 and the peripheral circuits.

 YES

Does the drive output circuit normally work?

NO

Check MOS7500-3, etc. and the  peripheral circuits.

 YES

Does the secondary side of T7500-4 normally work?

NO

Check T7500-4, D7523-7, etc. and the  peripheral circuits.

 YES

Check the feedback circuits such as FB_LINE, 
FBK_LINE, FB_1_LINE, OVP_LINE.

LC-26D44E/S/RU-BK/GY

4 – 3

The sound is not emitted from the speaker though the picture has come out. 

No sound output in all modes.?

Is the audio signal output of pins (28/L) and (27/R) of 
IC3001 (MAIN_MICON) normal?

NO

Check IC3001 and its peripheral circuits.

 YES

Is audio signal input to pin(5/L), pin(9/R) of IC2701(AMP)?

NO

Check the line between IC3001 and IC2701.

 YES

Is MUTE circuit [MUTE_SP_LINE, RESET_N_LINE] nor-
mal?

NO

Check the MUTE_SP_LINE and RESET_N_LINE.
(Q2701, etc.)

 YES

Is the audio signal output of pins (3, 4) (L-ch) and (2, 1) 
(R-ch) of P2701(AOUDIO-CONNECTOR) normal?

NO

Check IC2701 and its peripheral circuits.

 YES

Check Speaker (right and left) and wire harness.

No sound (during the reception of TV(ANALOG) broadcasting)

Does not the sound go out though the picture has come out when UHF/VHF is received?

Is the SIF signal output from pin (4) of TUNER (TU201)?

NO

Check the tuner and its peripheral circuits.
Replace as required.

 YES

Is the SIF signal sent to pins (31) of IC3001 
(MAIN_MICON)?

NO

Check the line between TU201 and IC3001.

 YES

Refer to “No sound output in all modes”.

LC-26D44E/S/RU-BK/GY

4 – 4

No sound (during the reception of TV(DIGITAL) broadcasting)

Does not the sound go out though the picture has come out when DTV is received?

Is the audio signal output from PIN(24,25)/ LETFT_M/P, 
PIN(28,29)/ RIGH_M/P of  IC4001(SET-
TOP_BOX_DECODER).

NO

Check IC4001 and its peripheral circuits.

 

YES

Is the audio signal input to PIN(6,5)/ LETFT_M/P, (2,3)/ 
RIGH_M/P of  IC4005(OP-AMP)?

NO

Check the line between IC4001 and IC4005.

 YES

Is the audio signal sent from PIN(7)/ AIN1L, (1)/AIN1R of   
IC4005 to PIN(10), PIN(9) of IC3001 (MAIN_MICON)?

NO

Check the line between IC4005 and IC3001.

 

YES

Refer to “No sound output in all modes”.

No sound from external input devices (1)

Does not the sound of the audio signal input to EXT1(SCART1) go out?
Does not the sound of the audio signal input to EXT2(SCART2) go out?

EXT1
Is the audio signal properly sent to pins (6) (AIN3_L) and 
(2) (AIN3_R) of SCART1(SC1102)?

NO

Check the setting of an external input device that connects of 
SC1102.

EXT2
Is the audio signal properly sent to pins (6) (AIN2_L) and 
(2) (AIN2_R) of SCART2(SC1101)?

NO

Check the setting of an external input device that connects of 
SC1101.

 YES

EXT1
Is the audio signal properly sent to pins (14) (AIN3_L) and 
(13) (AIN3_R) of IC3001(MAIN_MICON)?

NO

Check the line between SC1102 and IC3001.

EXT2
Is the audio signal properly sent to pins (12) (AIN2_L) and 
(11) (AIN2_R) of IC3001(MAIN_MICON)?

NO

Check the line between SC1101 and IC3001.

 YES

Refer to “No sound output in all modes”.