Read Sharp LC-37GD8EK (serv.man10) Service Manual online
41
LC-26GA5E
LC-32GA5E
LC-32GD8E/RU
LC-32BT8E/RU
LC-37GD8E/RU
LC-37BT8E/RU
LC-32/37GD8E/RU
LC-32/37BT8E/RU
26
LC-32/37GD8E/RU
LC-32/37BT8E/RU
TROUBLESHOOTING TABLE
NO
YES
NO
YES
YES
NO
YES
YES
Power unit operation check
Are the power cord and harness in the unit properly connected?
Are both ends of C704 and C705 (32"/37") short-circuited when
checking their resistance values?
checking their resistance values?
Connect the power cord and harness properly, and turn on the
power.
power.
Is a voltage of BU5V applied to pin (20) of P701? (Set the main
power SW to OFF.)
power SW to OFF.)
C704 ••• Check VA701, VA702 and D701.
C705(32”/37”) ••• Check IC704 and 705.
C705(32”/37”) ••• Check IC704 and 705.
Is F701 normal?
Does the same symptom appear even if R858 (2.7k) is removed
and the power is supplied again?
and the power is supplied again?
Is a voltage of approx. 8 – 15V to pin (4) of IC705?
NO
Replace F701.
YES
Check short circuit of 5V line (D737, C752, etc.).
NO
Check IC705, IC708, D725
and Q724.
and Q724.
NO
Check IC704, D728, D762 and D736. If there are no problems,
check the resistance value between pins (1) and (6) of P704.
When the value is low (several
check the resistance value between pins (1) and (6) of P704.
When the value is low (several
Ω- several hundred Ω),
disconnect P704. If the value is still low, the parts of 24V line are
defective. When the resistance value is several k
defective. When the resistance value is several k
Ω, check the
inverter unit.
YES
Check Q724, D731, D734, IC707, D751, D753, D754, D741,
D759 and D746.
D759 and D746.
Does a relay noise sound? (Once)
YES
NO
Check peripheral circuits of D738, R828 and D735.
NO
Are PCON1 and 2 [pins (1) and (2) of P702] at Hi (3V or more)?
NO
There is a possibility that control by P-CON is not performed
properly. Check whether the "PS-ON" and "PS-ON2" signals are
sent from pins (97) and (91) of IC1710 (FPGA) of MAIN-UNIT.
properly. Check whether the "PS-ON" and "PS-ON2" signals are
sent from pins (97) and (91) of IC1710 (FPGA) of MAIN-UNIT.
YES
Check peripheral circuits of Q712, Q713, Q721, Q723 and
RY701.
RY701.
Is it a symptom that the relay clatters twice as soon as the main
power SW is set to ON and the power is not supplied?
power SW is set to ON and the power is not supplied?
TROUBLESHOOTING TABLE
42
LC-26GA5E
LC-32GA5E
LC-32/37GD8E/RU
LC-32/37BT8E/RU
27
LC-32/37GD8E/RU
LC-32/37BT8E/RU
TROUBLESHOOTING TABLE
(Continued)
No sound (1) (during the reception of TV broadcasting)
No audio output during UHF/VHF reception
Checklist:
1) Is the volume set to MIN or MUTE on the remote control? ··· Set the desired volume.
2) Are headphones connected to HEADPHONE (J1301)? ··· Disconnect them.
3) Is ANT-CABLE disconnected or connected improperly? ··· Connect it correctly as per the operation manual.
1) Is the volume set to MIN or MUTE on the remote control? ··· Set the desired volume.
2) Are headphones connected to HEADPHONE (J1301)? ··· Disconnect them.
3) Is ANT-CABLE disconnected or connected improperly? ··· Connect it correctly as per the operation manual.
NO
Is the audio signal (L/R) sent from pins (28) and (27) of IC3002
(VCT)?
(VCT)?
NO
YES
Is the audio signal of pins (3)
and (5) of IC303 (OP-AMP)
sent properly?
and (5) of IC303 (OP-AMP)
sent properly?
(AV-UNIT)
(TUNER)
Check IC303 or peripheral
circuits.
circuits.
NO
YES
YES
Is the audio signal of pin (4)
of IC301/IC302 (AUDIO-
AMP) sent properly?
of IC301/IC302 (AUDIO-
AMP) sent properly?
Check HEAD-PHONE
(J1301) or peripheral
circuits.
(J1301) or peripheral
circuits.
NO
Is the audio signal output of
pins (2) and (4) of P301
(AUDIO-CONNECTOR)
normal?
pins (2) and (4) of P301
(AUDIO-CONNECTOR)
normal?
YES
Check Speaker (right and
left) and wire harness.
left) and wire harness.
Check P301 (AUDIO-
CONNECTOR) and
peripheral circuits.
CONNECTOR) and
peripheral circuits.
YES
NO
Is the audio signal (SIF) sent
from pin (1) of CONNECTOR
(SC2705)?
from pin (1) of CONNECTOR
(SC2705)?
Check pin (31) of IC3002
(VCT) and peripheral
circuits.
(VCT) and peripheral
circuits.
YES
Is the SIF signal (SIF_IN+)
sent to pin (31) of IC3002
(VCT)?
sent to pin (31) of IC3002
(VCT)?
Check whether +5V and +8V
are supplied to pins (33) and
(18) of IC3002 respectively.
Or, check peripheral circuits.
are supplied to pins (33) and
(18) of IC3002 respectively.
Or, check peripheral circuits.
YES
NO
NO
NO
NO
Is the audio signal (SIF) sent
from pin (12) of IC201 (IF-
DEMOD)?
from pin (12) of IC201 (IF-
DEMOD)?
Check Q203 (AMP) and
peripheral circuits.
peripheral circuits.
YES
Is the SIF signal sent to pins
(23) and (24) of IC201 (IF-
DEMOD)?
(23) and (24) of IC201 (IF-
DEMOD)?
Check IC201 and peripheral
circuits.
circuits.
YES
Is the IF signal sent from pin
(8) of TUNER (TU201)?
(8) of TUNER (TU201)?
Check FL202 and peripheral
circuits.
circuits.
YES
Check whether 5V (CONT)
and 5V are supplied to pins
(1) and (7) of TUNER
(TU201) respectively. Check
SDA/SCL and AGC signal.
and 5V are supplied to pins
(1) and (7) of TUNER
(TU201) respectively. Check
SDA/SCL and AGC signal.
Replace TUNER (TU201).
Troubleshooting Table (continued)
43
LC-26GA5E
LC-32GA5E
LC-32GD8E/RU
LC-32BT8E/RU
LC-37GD8E/RU
LC-37BT8E/RU
LC-32/37GD8E/RU
LC-32/37BT8E/RU
28
LC-32/37GD8E/RU
LC-32/37BT8E/RU
No sound from external input devices (2)
No sound from an external
input device connected to
EXT1 (SCART1).
input device connected to
EXT1 (SCART1).
No sound from an external
input device connected to
EXT2 (SCART2).
input device connected to
EXT2 (SCART2).
No sound from an
external input device
connected to EXT3.
external input device
connected to EXT3.
No sound from EXT4
(AUDIO) connecting an
external input device.
(AUDIO) connecting an
external input device.
No sound from EXT5
(AUDIO) connecting an
external input device.
(AUDIO) connecting an
external input device.
YES
<EXT1>
Is IN1-L audio signal sent
from pin (6) of SCART1
terminal (J1101) to pin
(14) of IC3002 (VCT)?
Is IN1-R audio signal sent
from pin (2) of SCART1
terminal (J1101) to pin
(13) of IC3002 (VCT)?
Is IN1-L audio signal sent
from pin (6) of SCART1
terminal (J1101) to pin
(14) of IC3002 (VCT)?
Is IN1-R audio signal sent
from pin (2) of SCART1
terminal (J1101) to pin
(13) of IC3002 (VCT)?
<EXT2>
Is IN2-L audio signal sent
from pin (27) of SCART2
terminal (J1101) to pin
(12) of IC3002 (VCT)?
Is IN2-R audio signal sent
from pin (23) of SCART2
terminal (J1101) to pin
(11) of IC3002 (VCT)?
Is IN2-L audio signal sent
from pin (27) of SCART2
terminal (J1101) to pin
(12) of IC3002 (VCT)?
Is IN2-R audio signal sent
from pin (23) of SCART2
terminal (J1101) to pin
(11) of IC3002 (VCT)?
<EXT3>
Is IN3-L audio signal
sent from pin (3) of
J1201 terminal to pin
(16) of IC3002?
Is IN3-R audio signal
sent from pin (5) of
J1201 terminal to pin
(15) of IC3002?
Is IN3-L audio signal
sent from pin (3) of
J1201 terminal to pin
(16) of IC3002?
Is IN3-R audio signal
sent from pin (5) of
J1201 terminal to pin
(15) of IC3002?
Is the audio signal
properly sent from pins
(28) and (27) of IC3002?
properly sent from pins
(28) and (27) of IC3002?
Check IC3002 or
peripheral circuits.
peripheral circuits.
Is the audio signal of
pins (1) and (7) of IC303
(OP-AMP) sent properly?
pins (1) and (7) of IC303
(OP-AMP) sent properly?
Check IC303 or
peripheral circuits.
peripheral circuits.
<EXT4>
Is D-SUB-L audio signal
sent from J2702 to pin
(15) of IC2704?
Is D-SUB-R audio signal
sent from J2702 to pin
(2) of IC2704?
Is D-SUB-L audio signal
sent from J2702 to pin
(15) of IC2704?
Is D-SUB-R audio signal
sent from J2702 to pin
(2) of IC2704?
Is D-SUB-L audio signal
sent to pin (10) of
IC3002?
Is D-SUB-R audio signal
sent to pin (9) of
IC3002?
sent to pin (10) of
IC3002?
Is D-SUB-R audio signal
sent to pin (9) of
IC3002?
<EXT5>
Is HDMI-L audio signal
sent from J2701 to pin
(14) of IC2704?
Is HDMI-R audio signal
sent from J2701 to pin
(5) of IC2704?
Is HDMI-L audio signal
sent from J2701 to pin
(14) of IC2704?
Is HDMI-R audio signal
sent from J2701 to pin
(5) of IC2704?
Check pins (6) and
(2) of SCART1 and
connection to an
external input
device.
(2) of SCART1 and
connection to an
external input
device.
Check pins (27) and
(23) of SCART2 and
connection to an
external input
device.
(23) of SCART2 and
connection to an
external input
device.
Check pins 3
(J1201) and 5
(J1201) of EXT3
and connection to
an external input
device.
(J1201) and 5
(J1201) of EXT3
and connection to
an external input
device.
Is HDMI-L audio
signal sent to pin
(10) of IC3002?
Is HDMI-R audio
signal sent to pin (9)
of IC3002?
signal sent to pin
(10) of IC3002?
Is HDMI-R audio
signal sent to pin (9)
of IC3002?
Is the audio output
signal of pins (13) and
(16) of IC302/IC301
(MAIN-AMP) normal?
signal of pins (13) and
(16) of IC302/IC301
(MAIN-AMP) normal?
Check IC302/IC301
(MAIN-AMP),
HEADPHONE and
peripheral circuits.
(MAIN-AMP),
HEADPHONE and
peripheral circuits.
Check CONNECTOR
(P301) and Speaker
(right and left).
(P301) and Speaker
(right and left).
YES
YES
NO
NO
Check output of pins
(13) and (3) of
IC2704 and
peripheral circuits.
(13) and (3) of
IC2704 and
peripheral circuits.
NO
Check that Option-
HDMI Setup-Audio
select is set to
"Analog".
HDMI Setup-Audio
select is set to
"Analog".
YES
YES
YES
OK
NO
YES
YES
YES
NO
YES
NO
NO
TROUBLESHOOTING TABLE
(Continued)
Troubleshooting Table (continued)
44
LC-26GA5E
LC-32GA5E
LC-32/37GD8E/RU
LC-32/37BT8E/RU
29
LC-32/37GD8E/RU
LC-32/37BT8E/RU
TROUBLESHOOTING TABLE
(Continued)
No sound except from speakers (3)
Check audio input signal of pin (31) of IC3002 (VCT), pins (18)
and (33) of the power line, pins (84) and (83) of I2C-LINE, and
peripheral circuits.
and (33) of the power line, pins (84) and (83) of I2C-LINE, and
peripheral circuits.
NO
NO
NO
NO
No audio output from the
headphones
headphones
No audio output from EXT1
(SCART) terminal.
(SCART) terminal.
NO
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)
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?
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?
NO
NO
YES
YES
NO
YES
NO
NO
NO
YES
YES
Is audio output signal (SPK-
OUT L/R) properly sent from
pins (28) and (27) of IC3002
(VCT)?
OUT L/R) properly sent from
pins (28) and (27) of IC3002
(VCT)?
Check the connection to
EXT1 (J1101) and external
devices.
EXT1 (J1101) and external
devices.
Check the connection to
EXT2 (J1101) and external
devices.
EXT2 (J1101) and external
devices.
Is S-MUTE-LINE [IC1710 (pin
100)] or S2-MUTE-LINE
[IC3003 (pin 26)] at H?
(Check Q1102/Q1101
operation.)
100)] or S2-MUTE-LINE
[IC3003 (pin 26)] at H?
(Check Q1102/Q1101
operation.)
Is audio signal sent from pins
(22) and (21) of IC3002?
(22) and (21) of IC3002?
Check the audio signal
output line from pins (22) and
(21) of IC3002 to
Q1103/Q1104/Q1201/Q1202.
output line from pins (22) and
(21) of IC3002 to
Q1103/Q1104/Q1201/Q1202.
Check the connection to
AUDIO OUTPUT terminal
(J1201) and external devices.
AUDIO OUTPUT terminal
(J1201) and external devices.
Is S-MUTE-LINE [IC1710 (pin
100)] at H?
(Check Q1204/Q1203
operation.)
100)] at H?
(Check Q1204/Q1203
operation.)
Is audio signal sent to pins
(3) and (1) of EXT1 (J1101)?
(3) and (1) of EXT1 (J1101)?
Is S-MUTE-LINE [IC1710
(pin 100)] at H?
(Check Q1106/Q1105
operation.)
(pin 100)] at H?
(Check Q1106/Q1105
operation.)
Is audio signal sent from
pins (24) and (23) of
IC3002?
pins (24) and (23) of
IC3002?
Check the audio signal
output line from pins (24)
and (23) of IC3002 to pins
(3) and (1) of EXT1.
output line from pins (24)
and (23) of IC3002 to pins
(3) and (1) of EXT1.
Check the power supply 8/5
V pins (18) and (33) of
IC3002 and peripheral
circuits.
V pins (18) and (33) of
IC3002 and peripheral
circuits.
Is audio signal sent to pins
(24) and (22) of EXT2
(J1101)?
(24) and (22) of EXT2
(J1101)?
Is audio signal sent to pins
(13) and (15) [L/R (white)
(red)] of AUDIO OUTPUT
terminal (J1201)?
(13) and (15) [L/R (white)
(red)] of AUDIO OUTPUT
terminal (J1201)?
No audio output from EXT2
(SCART) terminal.
(SCART) terminal.
No audio output from AUDIO
OUTPUT terminal.
OUTPUT terminal.
Is the MUTE button on the
remote control set to ON?
... Set to OFF.
29
LC-32/37GD8E/RU
LC-32/37BT8E/RU
TROUBLESHOOTING TABLE
(Continued)
No sound except from speakers (3)
Check audio input signal of pin (31) of IC3002 (VCT), pins (18)
and (33) of the power line, pins (84) and (83) of I2C-LINE, and
peripheral circuits.
and (33) of the power line, pins (84) and (83) of I2C-LINE, and
peripheral circuits.
NO
NO
NO
NO
No audio output from the
headphones
headphones
No audio output from EXT1
(SCART) terminal.
(SCART) terminal.
NO
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)
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?
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?
NO
NO
YES
YES
NO
YES
NO
NO
NO
YES
YES
Is audio output signal (SPK-
OUT L/R) properly sent from
pins (28) and (27) of IC3002
(VCT)?
OUT L/R) properly sent from
pins (28) and (27) of IC3002
(VCT)?
Check the connection to
EXT1 (J1101) and external
devices.
EXT1 (J1101) and external
devices.
Check the connection to
EXT2 (J1101) and external
devices.
EXT2 (J1101) and external
devices.
Is S-MUTE-LINE [IC1710 (pin
100)] or S2-MUTE-LINE
[IC3003 (pin 26)] at H?
(Check Q1102/Q1101
operation.)
100)] or S2-MUTE-LINE
[IC3003 (pin 26)] at H?
(Check Q1102/Q1101
operation.)
Is audio signal sent from pins
(22) and (21) of IC3002?
(22) and (21) of IC3002?
Check the audio signal
output line from pins (22) and
(21) of IC3002 to
Q1103/Q1104/Q1201/Q1202.
output line from pins (22) and
(21) of IC3002 to
Q1103/Q1104/Q1201/Q1202.
Check the connection to
AUDIO OUTPUT terminal
(J1201) and external devices.
AUDIO OUTPUT terminal
(J1201) and external devices.
Is S-MUTE-LINE [IC1710 (pin
100)] at H?
(Check Q1204/Q1203
operation.)
100)] at H?
(Check Q1204/Q1203
operation.)
Is audio signal sent to pins
(3) and (1) of EXT1 (J1101)?
(3) and (1) of EXT1 (J1101)?
Is S-MUTE-LINE [IC1710
(pin 100)] at H?
(Check Q1106/Q1105
operation.)
(pin 100)] at H?
(Check Q1106/Q1105
operation.)
Is audio signal sent from
pins (24) and (23) of
IC3002?
pins (24) and (23) of
IC3002?
Check the audio signal
output line from pins (24)
and (23) of IC3002 to pins
(3) and (1) of EXT1.
output line from pins (24)
and (23) of IC3002 to pins
(3) and (1) of EXT1.
Check the power supply 8/5
V pins (18) and (33) of
IC3002 and peripheral
circuits.
V pins (18) and (33) of
IC3002 and peripheral
circuits.
Is audio signal sent to pins
(24) and (22) of EXT2
(J1101)?
(24) and (22) of EXT2
(J1101)?
Is audio signal sent to pins
(13) and (15) [L/R (white)
(red)] of AUDIO OUTPUT
terminal (J1201)?
(13) and (15) [L/R (white)
(red)] of AUDIO OUTPUT
terminal (J1201)?
No audio output from EXT2
(SCART) terminal.
(SCART) terminal.
No audio output from AUDIO
OUTPUT terminal.
OUTPUT terminal.
Troubleshooting Table (continued)