Read Sharp LC-37GA5E (serv.man6) Service Manual online
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LC-26GA5E
LC-32GA5E
LC-32GA5E
LC-37GA5E
TROUBLESHOOTING TABLE
Previously to start following the behing troubleshooting tables, consider the below situa-
tions.
tions.
• Is the AC cord disconnected?
• Has the power been turned on?
• Make sure the
• Has the power been turned on?
• Make sure the
a (POWER) switch of the TV is set to ON.
• External influences such as lightning, static electricity, etc., may cause improper
operation. In this case, operate the unit after first turning the power off, or
unplugging the AC cord and re-plugging it in after 1 or 2 minutes.
unplugging the AC cord and re-plugging it in after 1 or 2 minutes.
• Are batteries inserted with polarity (e, f) aligned?
• Are batteries worn out? (Replace with new batteries.)
• Are you using it under strong or fluorescent lighting?
• Is a fluorescent light illuminated to remote control sensor?
• Are batteries worn out? (Replace with new batteries.)
• Are you using it under strong or fluorescent lighting?
• Is a fluorescent light illuminated to remote control sensor?
• Adjust the picture levels.
• Is the room too bright? The picture may look dark in a room that is too bright.
• Check the system setting.
• Check the input type setting.
• Is the room too bright? The picture may look dark in a room that is too bright.
• Check the system setting.
• Check the input type setting.
• The unit’s internal temperature has increased.
Remove any objects blocking vent or clean.
• Check the power control setting.
• Is connection to other components correct?
• Has input type setup been done correctly after connection?
• Is the correct input selected?
• Is a non-compatible signal being input?
• Is picture adjustment correct?
• Is the antenna connected properly?
• Has input type setup been done correctly after connection?
• Is the correct input selected?
• Is a non-compatible signal being input?
• Is picture adjustment correct?
• Is the antenna connected properly?
• Is the volume too low?
• Make sure that headphones are not connected.
• Make sure the sound is not set to Mute.
• Make sure that headphones are not connected.
• Make sure the sound is not set to Mute.
Cautions regarding use in high and low temperature environments
• When the unit is used in a low temperature space (e.g. room, office), the picture may leave trails or appear slightly
delayed. This is not a malfunction, and the unit will recover when the temperature returns to normal.
• Do not leave the unit in a hot or cold location. Also, do not leave the unit in a location exposed to direct sunlight or near
a heater, as this may cause the cabinet to deform and the LCD panel to malfunction.
Storage temperature: –20°C to +60°C (–4°F to +140°F).
Storage temperature: –20°C to +60°C (–4°F to +140°F).
Problem
Possible Solution
• No power.
• Unit cannot be operated.
• Remote control unit does not
operate.
• Strange colour, light colour, or
dark, or colour misalignment.
• Power is suddenly turned off.
• No picture.
• No sound.
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Troubleshooting Table (continued)
<Power supply>
No power supply (Front LED is off) and no power-up. (Front LED does not change from red to green)
Is the power supply cord properly connected to the Main unit?
Replace F701 and F702, and then turn on the power. If a fuse
still blows, replace VA702, D701 and IC701, and then check again.
still blows, replace VA702, D701 and IC701, and then check again.
Replace F703 and then turn on the power. If a fuse still blows,
replace D763 and IC703, and then check again.
replace D763 and IC703, and then check again.
Are F701 and F702 normal?
Is F703 normal?
YES
YES
Reconnect the power supply cord and turn on the power.
NO
NO
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
Are the wire harness, FFC, etc. in the set connected properly?
Reconnect the wire harness, FFC, etc. and check again.
Is a voltage of about 380 V applied to C709 and C710 when
power is turned on?
power is turned on?
Check the 380V system power supply circuit. (L703, IC701,
Q701~5, D705, TH701)
Q701~5, D705, TH701)
Is thermal fuse (F704) normal? (117°C specification)
After replacing F704 and rechecking the mounting of D701,
D705, Q701, Q702, Q710 and Q711, supply power again. If the
fuse burns out again, replace the said parts and recheck.
D705, Q701, Q702, Q710 and Q711, supply power again. If the
fuse burns out again, replace the said parts and recheck.
Is voltage generated at the +13V line (pin 1 of CN706)
immediately after supplying power?
immediately after supplying power?
Check the power supply circuit of the 13V system.
(T701, T702, F704, Q706-14, PC701, PC703-4, D708-17,
IC702, L710, Q733-6, D735-6, D771, IC706)
Is "H" signal sent to the PS_ON (pin 5 of CN707) line?
(T701, T702, F704, Q706-14, PC701, PC703-4, D708-17,
IC702, L710, Q733-6, D735-6, D771, IC706)
Is "H" signal sent to the PS_ON (pin 5 of CN707) line?
Is +3.3V line (pins 11/12 of CN706) normal immediately after
supplying power?
Is F1001 (2.5A) of the Main PWB normal?
supplying power?
Is F1001 (2.5A) of the Main PWB normal?
Check the power supply circuit of the +3.3V line system.
(IC715, L715, T703, IC703, PC701-702) (F1001)
(IC715, L715, T703, IC703, PC701-702) (F1001)
Is each REG-IC output normal?
(IC708 (4V), IC740 (33V), IC709 (5V), IC713 (12V), Q760 (6V))
(IC708 (4V), IC740 (33V), IC709 (5V), IC713 (12V), Q760 (6V))
Check each REG-IC and each line.
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NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
No audio output (1) (On the reception of TV broadcasting)
No audio output on the reception of
UHF/VHF
.
Confirmation of the settings:
1) Is volume of REMOCON set to MIN or MUTE?
… Set to any value.
2)
Are headphones connected to HEADPHONE (J402)?
… Disconnect.
3) Is
ANT
-CABLE disconnected or is there a connection error?
… Connect according to the operation manual.
4) Is "VOLUME" in MENU-SOUND-LEVELS-SPEAKERS-VOLUME set to
"MIN=0"? … Set to the desired value between
"0-100".
Are audio signals (SPL/R) sent from the
pins (123)(124) of IC1001 (VCTI)?
Are audio signals of the pins (1)(7) of
IC1351 sent normally?
Are audio input signals of the pins (1
1
)(15)
of IC1301 (AUDIO-AMP-IC) normal?
Are audio output signals of the pins
(28)(31)/(24)(27) of IC1301 (AUDIO-AMP-
IC) normal?
Check the connector (P1301) and the left
and right SP-boxes.
Check IC1351 or its peripheral
circuits.
Check the HEADPHONE JACK
(J402) or its peripheral circuits.
Check IC1301 and its peripheral
circuits.
Are IF signals (IF+/IF-) sent
to the pins
(109)(1
10) of IC1001 (VCTI)?
Is IF signal sent from the pin (1
1
) of
TUNER (TU1201)?
Check if power of 33V/5V is supplied to
the pins (9)/(7) of
TUNER (TU1201). Or
check its peripheral parts.
Check if +8V
, +5V
and +3.3V are supplied
to the pins (126), (106) and (105) of
IC1001respectively
. Or check its
peripheral circuits.
Check SF1201 and its peripheral circuits.
Troubleshooting Table (continued)
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No audio output (2) (On the reception of TV broadcasting, audio from the EXT.
terminal to the external device)
terminal to the external device)
No audio output from EXT1 Terminal.
No audio output from EXT2 and EXT3
Terminals.
Terminals.
YES
Is output (A-OUT-L/R) of Pins
(120)(119) of IC1001 (VCTI) normal?
(120)(119) of IC1001 (VCTI) normal?
YES
Are the signals between pins (120)(119)
of IC1001 and pins (1)(3) of SCART2
(SC1452) normal?. Are the signals
between pins (120)(119) of IC1001 and
pins (5)(8) of SCART3 (J401) normal?.
IC1402
of IC1001 and pins (1)(3) of SCART2
(SC1452) normal?. Are the signals
between pins (120)(119) of IC1001 and
pins (5)(8) of SCART3 (J401) normal?.
IC1402
Check (Q1012, Q1406, Q1408) and
(Q1013, Q1403, Q1404) of the S-Mute
circuit.
(Q1013, Q1403, Q1404) of the S-Mute
circuit.
YES
Is output (A-OUT-L/R) of Pins
(122)(121) of IC1001 (VCTI) normal?
(122)(121) of IC1001 (VCTI) normal?
YES
Are the signals (A-OUT-L/R) between
pins (122)(121) of IC1001 and pins
(1)(3) of SCART1 (SC1451) normal?.
pins (122)(121) of IC1001 and pins
(1)(3) of SCART1 (SC1451) normal?.
Check Q1011, Q1004 and Q1005 of the
2S-Mute circuit and 2S-MUTE-LINE.
2S-Mute circuit and 2S-MUTE-LINE.
Troubleshooting Table (continued)
