Read Sharp LC-42X20E (serv.man4) Service Manual online
LC-42XL2E/S/RU, LC-46XL2E/S/RU, LC-46X20E/S/RU, LC-52XL2E/S/RU, LC-52X20E/S/RU
4 – 1
LC42XL2E
Service Manual
CHAPTER 4.
TROUBLESHOOTING TABLE
[1] TROUBLESHOOTING TABLE
Power unit operation check.
Are the power cord and harness in the unit properly connected?
NO
Connect the power cord and harness properly, and turn on the
power.
power.
LINE_FILTER_UNIT:
YES
Is F7000 normal?
NO
LINE_FILTER_UNIT:
Isn't FL7001, L7001, R7002, CX7000-1, Z7000, etc. out of order?
Moreover, whether the short-circuit with the circumference circuit
is checked.
POWER_UNIT:
BD7000, TH7000-1, IC7801,Z7800, etc. out of order?
Moreover, whether the short-circuit with the circumference circuit
is checked.
Isn't FL7001, L7001, R7002, CX7000-1, Z7000, etc. out of order?
Moreover, whether the short-circuit with the circumference circuit
is checked.
POWER_UNIT:
BD7000, TH7000-1, IC7801,Z7800, etc. out of order?
Moreover, whether the short-circuit with the circumference circuit
is checked.
POWER_UNIT
YES
Is B_BUS (+320V) output? (Set the main power SW to OFF.)
* When power on/off switch is on
• • • About +400V
NO
Does the PFC circuit operate normally?
(L7800, L7801, T7800, D7806, Q7804-5, IC7800-1 and etc. And,
the circuit around the protection circuit etc. is checked.)
(L7800, L7801, T7800, D7806, Q7804-5, IC7800-1 and etc. And,
the circuit around the protection circuit etc. is checked.)
YES
Is a voltage of BU5V applied to pin (8) of connector (PD)?
(Set the main power SW to OFF.)
(Set the main power SW to OFF.)
NO
Does the switching circuit operate normally?
Check circuit around the primary side (T7901, IC7905, Q7902,
Q7912-3, D7908-9, D7904, D7910, etc.), the secondary side
(D7918, L7900, etc.), the AC_DET circuit (D7911-2, IC7909,
IC7902, Q7910, Q7901, etc.), and the protection circuit.
Check circuit around the primary side (T7901, IC7905, Q7902,
Q7912-3, D7908-9, D7904, D7910, etc.), the secondary side
(D7918, L7900, etc.), the AC_DET circuit (D7911-2, IC7909,
IC7902, Q7910, Q7901, etc.), and the protection circuit.
YES
Are INV60V, UR15, and S15V output as for the power on/off
switch when it is on?
switch when it is on?
NO
Does the inverter circuit operate normally?
Check circuit around the primary side (T7001, T7601, IC7603,
IC7601, IC7600, Q7600-2, D7608, D7610, D7613, etc.), the sec-
ondary side (D7560-3, L7560, D7150-1, L7150, L7152, Q7911,
etc.), the PS_ON circuit (Q7300-1, etc.), and the protection cir-
cuit.
Check circuit around the primary side (T7001, T7601, IC7603,
IC7601, IC7600, Q7600-2, D7608, D7610, D7613, etc.), the sec-
ondary side (D7560-3, L7560, D7150-1, L7150, L7152, Q7911,
etc.), the PS_ON circuit (Q7300-1, etc.), and the protection cir-
cuit.
YES
Similarly, is PNL12V output as for the power on/off switch when it
is on?
is on?
NO
Check PNL_POW circuit of Q7121-2, etc. and the circuit around
the regulator circuit etc. of IC7121, L7121, D7121, etc.
the regulator circuit etc. of IC7121, L7121, D7121, etc.
LC-42XL2E/S/RU, LC-46XL2E/S/RU, LC-46X20E/S/RU, LC-52XL2E/S/RU, LC-52X20E/S/RU
4 – 2
The sound is not emitted from the speaker though the picture has come out.
No sound output in all modes?
TEREMINAL UNIT:
Is the audio signal output of pins (38) (L-ch) and (39) (R-ch) of
IC1404 (CODEC) normal?
Is the audio signal output of pins (38) (L-ch) and (39) (R-ch) of
IC1404 (CODEC) normal?
NO
Check IC1404 and its peripheral circuits.
YES
Is audio signal input to pin (5/L), pin (9/R) of IC1301 (AMP)?
NO
Check the line between IC1404 and IC1301.
YES
Is MUTE circuit [SP_MUTE_LINE, S_STBY_LINE] normal?
NO
Check the SP_MUTE_LINE and S_STBY_LINE.
(Q1302, etc.)
(Q1302, etc.)
YES
Is the audio signal output of pins (2, 1) (L-ch) and (3, 4) (R-ch) of
P1301(AOUDIO-CONNECTOR) normal?
P1301(AOUDIO-CONNECTOR) normal?
NO
Check IC1301 and its peripheral circuits.
YES
Check Speaker Box (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?
TEREMINAL UNIT:
Is the IF signal output from pin (17) of TUNER (TU7501)?
Is the IF signal output from pin (17) of TUNER (TU7501)?
NO
Check the tuner and its peripheral circuits.
Replace as required.
Replace as required.
YES
Is the SIF signal sent to pins (23) and (24) of IC7504 (IFDE-
MOD)?
MOD)?
NO
Check FL7501 and its peripheral circuits.
YES
Is the SIF signal input from pin (12) of IC7504 to pin (3) of IC1402
(SOUND MULTIPLEX DECODER)?
(SOUND MULTIPLEX DECODER)?
NO
Check the line between IC7504 and IC1402.
(Q7504, etc.)
(Q7504, etc.)
YES
Is audio signal input from pin (24/L-ch), (22/R-ch) of IC1402 to
pin (61, 62) of IC1404 (CODEC)?
pin (61, 62) of IC1404 (CODEC)?
NO
Check the line between IC1402 and IC1404.
YES
Refer to “No sound output in all modes”.
LC-42XL2E/S/RU, LC-46XL2E/S/RU, LC-46X20E/S/RU, LC-52XL2E/S/RU, LC-52X20E/S/RU
4 – 3
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?
MAIN UNIT:
Is DTV_SPDIF audio signal output from pin (T2) of IC8101 (CPU/
DECODER) to pin (42) of connector SC1101?
Is DTV_SPDIF audio signal output from pin (T2) of IC8101 (CPU/
DECODER) to pin (42) of connector SC1101?
NO
Check the line between IC8101 and SC1101, and their peripheral
circuits.
circuits.
TERMINAL UNIT:
YES
Is DTV_SPDIF audio signal input from pin(42) of connector
SC501 to pin(4) of IC1404(CODEC)?
SC501 to pin(4) of IC1404(CODEC)?
NO
Check the line between SC501 and IC1404.
(SC1101/SC501, etc.)
(SC1101/SC501, etc.)
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?
TEREMINAL UNIT:
EXT1
Is the audio signal properly sent to pins (6) (IN1_L) and (2)
(IN1_R) of SCART1(SC502)?
EXT1
Is the audio signal properly sent to pins (6) (IN1_L) and (2)
(IN1_R) of SCART1(SC502)?
NO
Check the setting of an external input device that connects of
SC502.
SC502.
EXT2
Is the audio signal properly sent to pins (6) (IN2_L) and (2)
(IN2_R) of SCART2(SC503)?
Is the audio signal properly sent to pins (6) (IN2_L) and (2)
(IN2_R) of SCART2(SC503)?
NO
Check the setting of an external input device that connects of
SC503.
SC503.
YES
EXT1
Is the audio signal properly sent to pins (51) (IN1_L) and (52)
(IN1_R) of IC1404(CODEC)?
Is the audio signal properly sent to pins (51) (IN1_L) and (52)
(IN1_R) of IC1404(CODEC)?
NO
Check the line between SC502 and IC1404.
EXT2
Is the audio signal properly sent to pins (53) (IN2_L) and (54)
(IN2_R) of IC1404(CODEC)?
Is the audio signal properly sent to pins (53) (IN2_L) and (54)
(IN2_R) of IC1404(CODEC)?
NO
Check the line between SC503 and IC1404.
YES
Refer to “No sound output in all modes”.
LC-42XL2E/S/RU, LC-46XL2E/S/RU, LC-46X20E/S/RU, LC-52XL2E/S/RU, LC-52X20E/S/RU
4 – 4
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/IN3-L), (4/IN3-R) of input termi-
nal J901 to pin (3), (1) of connector P901?
Is audio signal output from pin (5/IN3-L), (4/IN3-R) of input termi-
nal J901 to pin (3), (1) of connector P901?
NO
Check connection of between from J901 to P901 and the exter-
nal input device.
nal input device.
TERMINAL UNIT:
YES
Is audio signal input to pin (3/IN3-L), (1/IN3-R) of connector
P501?
P501?
NO
Check the connector (P901/P501).
YES
Is audio signal input to pin (55/IN3-L), (56/IN3-R) of IC1404
(CODEC)?
(CODEC)?
NO
Check the line between P501 and IC1404.
YES
Is CVBS signal detection signal V3_PLUG signal from pin (7) in
input terminal J901 normal?
input terminal J901 normal?
NO
Check the connection to J901 and external devices.
YES
Is V3_PLUG signal input to pin (2) of IC506 (VIDEO SELEC-
TOR)?
TOR)?
NO
Everything from V3_PLUG_LINE J901 to pin (2) of IC506 is
checked. (connector P901/P501 and etc.)
checked. (connector P901/P501 and etc.)
YES
Refer to “No sound output in all modes”.
No sound from external input devices (3)
Does not the sound of the audio signal input to EXT4/5/6 (HDMI) go out?
Is picture of the signal input from EXT4/5/6 displayed?
NO
Refer to “Does not the picture of the HDMI signal input to EXT4/
5/6 go out?”.
5/6 go out?”.
MAIN UNIT:
YES
Is the HDMI_SPDIF audio signal output from pin (W12) of
IC3301 (VIDEO PROCESSOR) to pin (44) of connector
SC1101?
IC3301 (VIDEO PROCESSOR) to pin (44) of connector
SC1101?
NO
Check the line between IC3301 and SC1101, and their peripheral
circuits.
circuits.
TERMINAL UNIT:
YES
Is HDMI_SPDIF audio signal input from pin (44) of connector
SC501 to pin (5) of IC1404 (CODEC)?
SC501 to pin (5) of IC1404 (CODEC)?
NO
Check the line between SC501 and IC1404.
(SC1101/SC501, etc.)
(SC1101/SC501, etc.)
YES
Refer to “No sound output in all modes”.