Sharp LC-42XD1EA (serv.man4) Service Manual ▷ View online
LC-42XD1EA/RUA
4 – 5
No sound except from speakers (3) -1
No audio output from the
headphones.
headphones.
No audio output from
EXT1 (SCART) terminal.
EXT1 (SCART) terminal.
Is there audio output on pins
(2) and (3) of the headphone
terminal (J1301)?
(2) and (3) of the headphone
terminal (J1301)?
Checklist:
1) Is the MUTE button on the remote control set to ON? ... Set to OFF.
2) Check the connection to external devices....Is there any improper connection?
3) ls S-MUTE-LINE [IC1710 (pin 92)] at H?....It is defective. Check the IC1710.
1) Is the MUTE button on the remote control set to ON? ... Set to OFF.
2) Check the connection to external devices....Is there any improper connection?
3) ls S-MUTE-LINE [IC1710 (pin 92)] at H?....It is defective. Check the IC1710.
NO
Is audio input/output signal of
pins (3) and (5)/(1) and (7) of
IC303 (OP-AMP) normal?
pins (3) and (5)/(1) and (7) of
IC303 (OP-AMP) normal?
Is audio signal sent to pins
(3) and (1) of EXT1
(J1101)?
(3) and (1) of EXT1
(J1101)?
NO
ls S-MUTE-LINE
[IC1710 (pin 92)] at H?
(Check Q1106/Q1105
operation.)
[IC1710 (pin 92)] at H?
(Check Q1106/Q1105
operation.)
NO
YES
NO
Is audio output signal (SPK-
OUT L/R) properly sent from
pins (28) and (27) of IC3701
(MSP)?
OUT L/R) properly sent from
pins (28) and (27) of IC3701
(MSP)?
Check the connection to
EXT1 (J1101) and exter-
nal devices.
EXT1 (J1101) and exter-
nal devices.
Is audio signal sent
from pins (33) and (34)
of IC3701?
from pins (33) and (34)
of IC3701?
NO
Check the power supply
8/5 V pins (39) and (12)
of IC3701 and periph-
eral circuits.
8/5 V pins (39) and (12)
of IC3701 and periph-
eral circuits.
NO
YES
Check audio input signal of pin
(67) of IC3701(MSP), pins
(39) and (12) of the power
line5 and 8V, pins (3) and (2)
of I2C-LINE, and peripheral
circuits.
(67) of IC3701(MSP), pins
(39) and (12) of the power
line5 and 8V, pins (3) and (2)
of I2C-LINE, and peripheral
circuits.
Check the audio signal
output line from pins
(33) and (34) of IC3701
to pins (3) and (1) of
EXT1.
output line from pins
(33) and (34) of IC3701
to pins (3) and (1) of
EXT1.
LC-42XD1EA/RUA
4 – 6
No sound except from speakers (3) -2
No audio output from
EXT2 (SCART) termi-
nal.
EXT2 (SCART) termi-
nal.
No audio output from
AUDIO OUTPUT termi-
nal.
AUDIO OUTPUT termi-
nal.
Checklist:
1) Is the MUTE button on the remote control set to ON? ... Set to OFF.
2) Check the connection to external devices....Is there any improper connection?
3) ls S-MUTE-LINE [IC1710 (pin 92)] at H?....It is defective. Check the IC1710.
1) Is the MUTE button on the remote control set to ON? ... Set to OFF.
2) Check the connection to external devices....Is there any improper connection?
3) ls S-MUTE-LINE [IC1710 (pin 92)] at H?....It is defective. Check the IC1710.
Is audio signal sent to
pins (24) and (22) of
EXT2 (J1101)?
pins (24) and (22) of
EXT2 (J1101)?
NO
ls S-MUTE-LINE [IC1710
(pin 92)] or S2-MUTE-
LINE [IC1710(pin 90)] at
H?
(Check Q1102/Q1101
operation.)
(pin 92)] or S2-MUTE-
LINE [IC1710(pin 90)] at
H?
(Check Q1102/Q1101
operation.)
ls S-MUTE-LINE
[IC1710 (pin 92)] at H?
(Check 1204/Q1203
operation.)
[IC1710 (pin 92)] at H?
(Check 1204/Q1203
operation.)
NO
Is audio signal sent to
pins (13) and (15) [L/
R (white) (red)] of
AUDIO OUTPUT termi-
nal (J1201)?
pins (13) and (15) [L/
R (white) (red)] of
AUDIO OUTPUT termi-
nal (J1201)?
YES
NO
NO
YES
Check the connection to
EXT2 (J1101) and
external devices.
EXT2 (J1101) and
external devices.
Is audio signal sent from pins (36) and (37) of IC3701?
Check the connection
to AUDIO OUTPUT
terminal (J1201) and
external devices.
to AUDIO OUTPUT
terminal (J1201) and
external devices.
NO
YES
Check the power supply 8/
5 V pins (39) and (12) of
IC3701 and peripheral cir-
cuits.
5 V pins (39) and (12) of
IC3701 and peripheral cir-
cuits.
Check the audio signal
output line from pins
(36) and (37) of IC3701
to Q1103/Q1104/
Q1201/Q1202.
output line from pins
(36) and (37) of IC3701
to Q1103/Q1104/
Q1201/Q1202.
LC-42XD1EA/RUA
4 – 7
DTV troubleshooting 1
The unit does not enter
the DTV mode. Or, the
DTV menu does not
appear.
YES
Go to “The unit does not
enter the DTV mode. Or,
the DTV menu does not
appear.”
enter the DTV mode. Or,
the DTV menu does not
appear.”
The unit does not enter the DTV mode. Or, the DTV menu does not
appear.
appear.
NO
No video output during
DTV reception.
DTV reception.
YES
Go to “No video output
during DTV reception.”
during DTV reception.”
Digital UNIT:
Is a voltage supplied from
IC4701 (3.3V-REG)/
IC4704 (1.8V-REG)?
Is a voltage supplied from
IC4701 (3.3V-REG)/
IC4704 (1.8V-REG)?
NO
Check peripheral circuits
of IC4701/IC4704 and pin
(7) of IC4701.
of IC4701/IC4704 and pin
(7) of IC4701.
NO
YES
No audio output during
DTV reception.
DTV reception.
YES
Go to “No audio output
during DTV reception.”
during DTV reception.”
Do X4001/X4002
oscillate?
oscillate?
NO
Check peripheral circuits
of X4001/X4002.
of X4001/X4002.
YES
D-TUNER UNIT:
Is a voltage of 1.8/3.3V
supplied from IC205
(REG) and IC206 (REG)?
Is a voltage of 1.8/3.3V
supplied from IC205
(REG) and IC206 (REG)?
NO
Check peripheral circuits
of IC205/IC206.
of IC205/IC206.
YES
Is a voltage applied to pin
(20) (I2CSEL) of P202?
(High=3.3V)
(20) (I2CSEL) of P202?
(High=3.3V)
NO
MAIN UNIT:
Check around the pin (85)
of IC1710 (FPGA).
Check around the pin (85)
of IC1710 (FPGA).
YES
Is FESDA/FESCL signal
sent to pins (21) and (22)
of P202 and pins (21) and
(20) of IC202 (COFDM).
sent to pins (21) and (22)
of P202 and pins (21) and
(20) of IC202 (COFDM).
NO
Check peripheral circuits
of IC202 (COFDM)/
IC4001 (D-Processor).
of IC202 (COFDM)/
IC4001 (D-Processor).
YES
Does X-TAL X202 of
IC202 oscillate?
IC202 oscillate?
NO
Check peripheral circuits
of X202.
of X202.
YES
Check IC202 (COFDM)/
IC4001 (D-Processor).
IC4001 (D-Processor).
LC-42XD1EA/RUA
4 – 8
DTV troubleshooting 2
No video output during
DTV reception. Colors of
Images are not right.
DTV reception. Colors of
Images are not right.
No audio output during
DTV reception. Sound is
low.
DTV reception. Sound is
low.
D-TUNER UNIT:
Is data FED[0:7] sent from
pins (3), (4), (5), (6), (8),
(9), (10) and (11) of P202?
Is data FED[0:7] sent from
pins (3), (4), (5), (6), (8),
(9), (10) and (11) of P202?
NO
Check R272 and R273.
DIGITAL UNIT:
Is audio signal fed to pins
(5) and (10) of IC4604
(OP-AMP)?
Is audio signal fed to pins
(5) and (10) of IC4604
(OP-AMP)?
NO
Check R4002 (AD2pin)
and IC4001 (D-Proces-
sor).
and IC4001 (D-Proces-
sor).
YES
YES
DIGITAL UNIT:
Are video signals (R/G/B,
CVBS) sent from C4639/
C4640/C4641/C4625?
Are video signals (R/G/B,
CVBS) sent from C4639/
C4640/C4641/C4625?
NO
Check R4011 (AC8pin),
R4013 (AC9pin) and
IC4001 (D-Processor).
R4013 (AC9pin) and
IC4001 (D-Processor).
Is audio signal sent from
pins (7) and (8) of IC4604
(OP-AMP)?
pins (7) and (8) of IC4604
(OP-AMP)?
NO
Check power supply of
IC4604 (OP-AMP) and its
peripheral circuits.
IC4604 (OP-AMP) and its
peripheral circuits.
YES
YES
Are video signals (R/G/B,
CVBS) send from the
C4636/C4637/C4638 and
emitters of Q4607?
CVBS) send from the
C4636/C4637/C4638 and
emitters of Q4607?
NO
Check Q4601-Q4605,
Q4607 and their periph-
eral circuits.
Q4607 and their periph-
eral circuits.
MAIN UNIT:
Is audio signal sent to pin
(3) and (13) of IC2704
(SW)?
Is audio signal sent to pin
(3) and (13) of IC2704
(SW)?
NO
Check power supply and
control signal of pins (9)
and (10) of IC2704 (SW)
and audio signal input of
pins (4) and (11) of
IC2704.
control signal of pins (9)
and (10) of IC2704 (SW)
and audio signal input of
pins (4) and (11) of
IC2704.
YES
YES
MAIN UNIT:
Are video signals (R/G/B,
CVBS) fed from pins
(AA18), (AB18), (Y18) and
(AA21) of IC3002?
Are video signals (R/G/B,
CVBS) fed from pins
(AA18), (AB18), (Y18) and
(AA21) of IC3002?
Perform the same check
as the tuner (U/V) recep-
tion.
as the tuner (U/V) recep-
tion.
YES
Are scrambled images not
displayed?
displayed?
YES
DIGITAL UNIT:
Check 5V output of pin (1)
of IC4702.
Check 5V of pin (6) of
Q4401.
Check 5V output of pin (1)
of IC4702.
Check 5V of pin (6) of
Q4401.
NO
Perform the same check
as the tuner (U/V) recep-
tion.
as the tuner (U/V) recep-
tion.
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