Sharp LC-32SA1E (serv.man2) Service Manual ▷ View online
LC-26SA1E/RU, LC-32SA1E/RU
6 – 1
LC-26SA1E
Service Manual
CHAPTER 6.
TROUBLESHOOTING TABLE
[1] TROBLESHOOTING 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.
YES
Is F701 normal?
NO
Are both ends of C704, C707 (26) and C705 (32) short-circuited
when checking their resistance values?
when checking their resistance values?
YES
NO
YES
Replace F701.
Is a voltage of BU5V applied to pin (20) of P701?
(Set the main power SW to OFF.)
(Set the main power SW to OFF.)
C704
••• Check VA701, VA702 and D701.
C707 (26)/C705 (32)
••• Check IC704 and 705.
YES
NO
Is a voltage of approx.
8 - 15V to pin (4) of
IC705?
8 - 15V to pin (4) of
IC705?
NO
Check IC705, IC708, D725 and Q724.
YES
Check short circuit of 5V line (D737,
C752, etc.).
C752, etc.).
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?
NO
YES
Does the same symptom appear even if R858 (2.7k) is
removed and the power is supplied again?
removed and the power is supplied again?
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.
D741, D759 and D746.
Does a relay noise sound? (Once)
NO
Are PCON1 and 2 [pins (1) and (2) of P702] at Hi (3V or more)?
YES
YES
NO
Check peripheral circuits of D738, R828 and D735.
Check peripheral circuits of Q712, Q713, Q721, Q723
and RY701.
and RY701.
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.
LC-26SA1E/RU, LC-32SA1E/RU
6 – 2
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.
Is the audio signal (L/R)
sent from pins (28) and
(27) of IC3002 (VCT)?
NO
Is the SIF signal (SIF_IN+)
sent to pin (31) of IC3002
(VCT)?
sent to pin (31) of IC3002
(VCT)?
YES
Check whether +5V and
+8V are supplied to pins
(33) and (18) of IC3002
respectively. Or, check
peripheral circuits.
+8V are supplied to pins
(33) and (18) of IC3002
respectively. Or, check
peripheral circuits.
(AV-UNIT)
YES
NO
Is the audio signal of pins
(3) and (5) of IC303
(OP-AMP) sent properly?
(3) and (5) of IC303
(OP-AMP) sent properly?
NO
Check IC303 or
peripheral circuits.
peripheral circuits.
Is the audio signal (SIF)
sent from pin (1) of
CONNECTOR (SC2705)?
sent from pin (1) of
CONNECTOR (SC2705)?
YES
Check pin (31) of IC3002
(VCT) and peripheral
circuits.
(VCT) and peripheral
circuits.
YES
(TUNER) NO
Is the audio signal of pin
(4) Of IC301/IC302
(AUDIO-AMP) sent
properly?
(4) Of IC301/IC302
(AUDIO-AMP) sent
properly?
NO
Check HEAD-PHONE
(J1301) or peripheral
circuits.
(J1301) or peripheral
circuits.
Is the audio signal (SIF)
sent from pin (12) of IC201
(IF-DEMOD)?
sent from pin (12) of IC201
(IF-DEMOD)?
YES
Check Q203 (AMP) and
peripheral circuits.
peripheral circuits.
YES
NO
Is the audio signal output
of pins (2) and (4) of P301
(AUDIO-CONNECTOR)
normal?
of pins (2) and (4) of P301
(AUDIO-CONNECTOR)
normal?
NO
Check P301 (AUDIO-
CONNECTOR) and
peripheral circuits.
CONNECTOR) and
peripheral circuits.
Is the SIF signal sent to
pins (23) and (24) of IC201
(IF-DEMOD)?
pins (23) and (24) of IC201
(IF-DEMOD)?
YES
Check IC201 and
peripheral circuits.
peripheral circuits.
YES
NO
Check Speaker (right and
left) and wire harness.
left) and wire harness.
Is the IF signal sent from
pin (11) of TUNER
(TU201)?
pin (11) of TUNER
(TU201)?
YES
Check FL202 and
peripheral circuits.
peripheral circuits.
NO
Check whether 33V and
5V are supplied to pins (9)
and (7) of TUNER (TU201)
respectively. Check SDA/
SCL and AGC signal.
5V are supplied to pins (9)
and (7) of TUNER (TU201)
respectively. Check SDA/
SCL and AGC signal.
YES
Replace TUNER (TU201).
LC-26SA1E/RU, LC-32SA1E/RU
6 – 3
No sound from external input devices (2)
No sound from an external input device connected to EXT1
(SCART1).
<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)?
NO
Check pins (6) and (2) of SCART1 and connection to an external
input device.
input device.
YES
Is the audio signal properly sent from pins (28) and (27) of
IC3002?
IC3002?
NO
Check IC3002 or peripheral circuits.
YES
Is the audio signal of pins (1) and (7) of IC303 (OP-AMP) sent
properly?
properly?
NO
Check IC303 or peripheral circuits.
YES
Is the audio output signal of pins (13) and (16) of IC302/IC301
(MAIN-AMP) normal?
(MAIN-AMP) normal?
NO
Check IC302/IC301 (MAIN-AMP), HEADPHONE and peripheral
circuits.
circuits.
YES
Check CONNECTOR (P301) and Speaker (right and left).
No sound from external input devices (2)
No sound from an external input device connected to EXT2
(SCART2).
<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)?
NO
Check pins (27) and (23) of SCART2 and connection to an
external input device.
external input device.
YES
Is the audio signal properly sent from pins (28) and (27) of
IC3002?
IC3002?
NO
Check IC3002 or peripheral circuits.
YES
Is the audio signal of pins (1) and (7) of IC303 (OP-AMP) sent
properly?
properly?
NO
Check IC303 or peripheral circuits.
YES
Is the audio output signal of pins (13) and (16) of IC302/IC301
(MAIN-AMP) normal?
(MAIN-AMP) normal?
NO
Check IC302/IC301 (MAIN-AMP), HEADPHONE and peripheral
circuits.
circuits.
YES
Check CONNECTOR (P301) and Speaker (right and left).
LC-26SA1E/RU, LC-32SA1E/RU
6 – 4
No sound from external input devices (2)
No sound from an external input device connected to EXT3.
<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?
NO
Check pins (3) (J1201) and (5) (J1201) of EXT3 and connection
to an external input device.
to an external input device.
YES
Is the audio signal properly sent from pins (28) and (27) of
IC3002?
IC3002?
NO
Check IC3002 or peripheral circuits.
YES
Is the audio signal of pins (1) and (7) of IC303 (OP-AMP) sent
properly?
properly?
NO
Check IC303 or peripheral circuits.
YES
Is the audio output signal of pins (13) and (16) of IC302/IC301
(MAIN-AMP) normal?
(MAIN-AMP) normal?
NO
Check IC302/IC301 (MAIN-AMP), HEADPHONE and peripheral
circuits.
circuits.
YES
Check CONNECTOR (P301) and Speaker (right and left).
No sound from external input devices (2)
No sound from EXT4 (AUDIO) connecting an external input
device.
<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?
YES
Is D-SUB-L audio signal sent to pin (10) of IC3002?
Is D-SUB-R audio signal sent to pin (9) of IC3002?
Is D-SUB-R audio signal sent to pin (9) of IC3002?
YES
Is the audio signal properly sent from pins (28) and (27) of
IC3002?
IC3002?
NO
Check IC3002 or peripheral circuits.
YES
Is the audio signal of pins (1) and (7) of IC303 (OP-AMP) sent
properly?
properly?
NO
Check IC303 or peripheral circuits.
YES
Is the audio output signal of pins (13) and (16) of IC302/IC301
(MAIN-AMP) normal?
(MAIN-AMP) normal?
NO
Check IC302/IC301 (MAIN-AMP), HEADPHONE and peripheral
circuits.
circuits.
YES
Check CONNECTOR (P301) and Speaker (right and left).
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