Read Sharp LC-37D44EBK (serv.man6) Service Manual online
LC-37D44E/S/RU-BK/GY
4 – 1
LC37D44E-BK
Service Manual
CHAPTER 4.
TROUBLESHOOTING TABLE
[1] TROUBLESHOOTING TABLE
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?
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?
mal?
NO
Check the MUTE_SP_LINE and RESET_N_LINE.
(Q2701, etc.)
(Q2701, etc.)
YES
Is the audio signal output of pins (3, 4) (L-ch) and (2, 1)
(R-ch) of P2701(AOUDIO-CONNECTOR) normal?
(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.
Replace as required.
YES
Is the SIF signal sent to pins (31) of IC3001
(MAIN_MICON)?
(MAIN_MICON)?
NO
Check the line between TU201 and IC3001.
YES
Refer to “No sound output in all modes”.
LC-37D44E/S/RU-BK/GY
4 – 2
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).
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)?
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)?
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?
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)?
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.
SC1102.
EXT2
Is the audio signal properly sent to pins (6) (AIN2_L) and
(2) (AIN2_R) of SCART2(SC1101)?
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.
SC1101.
YES
EXT1
Is the audio signal properly sent to pins (14) (AIN3_L) and
(13) (AIN3_R) of IC3001(MAIN_MICON)?
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)?
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”.
LC-37D44E/S/RU-BK/GY
4 – 3
No sound from external input devices (2)
Does not the sound of the audio signal input to EXT3 go out?
MINI AV UNIT:
Is audio signal output from pin(5/IN3L), (4/IN3R) of input
terminal J1002 to pin(8), (6) of connector SC1001?
NO
Check connection of between from J1002 to SC1001 and the exter-
nal input device.
nal input device.
MAIN UNIT:
YES
Is audio signal input to pin(8/IN3L), (6/IN3R) of connector
P1001?
P1001?
NO
Check the connector(SC1001/ P1001).
YES
Is audio signal input to pin(1/IN3L), (6/IN3R) of IC1301
(AUDIO_SELECTOR)?
(AUDIO_SELECTOR)?
NO
Check the line between P1001 and IC1301.
YES
Is the audio signal sent to pin (15/AIN4L), (11/AIN4R) of
IC1301?
IC1301?
NO
Check IC1301 and its peripheral circuits.
YES
Is audio signal input from pin (15/AIN4L), (11/AIN4R) of IC1301 to pin (16, 15) of IC3001 (MAIN_MICON)?
YES
NO
Refer to “No sound output in all modes”
Check the line between IC1301 and IC3001.
No sound from external input devices (3)
Does not the sound of the audio signal input to EXT4 go
out?
out?
Does not the sound of the audio signal input to EXT6(Analog) go
out?
out?
Whether "Analog" has selected it in the Audio setup of the HDMI
option is checked.
option is checked.
Is audio signal sent from pin(2/L) and (3/R) of input termi-
nal J1301 to pin(5) and (8) of IC1301
(AUDIO_SELECTOR)?
nal J1301 to pin(5) and (8) of IC1301
(AUDIO_SELECTOR)?
YES
Is audio signal sent from pin(2/L) and (3/R) of input terminal J1302 to
pin(3) and (7) of IC1301(AUDIO_SELECTOR)?
pin(3) and (7) of IC1301(AUDIO_SELECTOR)?
NO
NO
Check the connection between J1301 and the peripheral
circuit, the external input devices.
circuit, the external input devices.
Check the connection between J1302 and the peripheral circuit, the
external input devices.
external input devices.
Is the audio signal sent to pin (15/AIN4L), (11/AIN4R) of
IC1301?
IC1301?
NO
Check IC1301 and its peripheral circuits.
LC-37D44E/S/RU-BK/GY
4 – 4
YES
Is audio signal input from pin (15/AIN4L), (11/AIN4R) of IC1301 to pin (16, 15) of IC3001 (MAIN_MICON)?
YES
NO
Refer to “No sound output in all modes”
Check the line between IC1301 and IC3001.
No sound from external input devices (4)
Does not the sound of the audio signal input to EXT5 go out?
Is audio signal output from pin(2/COMP_AL), (4/
COMP_AR) of input terminal J1303 to pin(13), (9) of
IC1301 (AUDIO_SELECTOR)?
COMP_AR) of input terminal J1303 to pin(13), (9) of
IC1301 (AUDIO_SELECTOR)?
NO
Check connection of between from J1303 to IC1301 and the external
input device.
input device.
YES
Is the audio signal sent to pin (15/AIN4L), (11/AIN4R) of
IC1301?
IC1301?
NO
Check IC1301 and its peripheral circuits.
YES
Is audio signal input from pin (15/AIN4L), (11/AIN4R) of IC1301 to pin (16, 15) of IC3001 (MAIN_MICON)?
YES
NO
Refer to “No sound output in all modes”
Check the line between IC1301 and IC3001.
No sound from external input devices (5)
Does not the sound of the audio signal input to EXT6/7(HDMI) go out?
Is picture of the signal input from EXT6/7 displayed?
NO
Refer to “Does not the picture of the HDMI signal input to EXT6/7 go
out?”.
out?”.
YES
Is the HDMI_SCK/ WS/ SD0 audio signal output from
pin(86), (85), (84) of IC1951 (HDMI RECEIVER) to pin(39),
(40), (38) of IC3001 (MAIN_MICON)?
pin(86), (85), (84) of IC1951 (HDMI RECEIVER) to pin(39),
(40), (38) of IC3001 (MAIN_MICON)?
NO
Check the line between IC1951 and IC3001, and their peripheral cir-
cuits.
cuits.
YES
Refer to “No sound output in all modes”.
