Sharp LC-26GA5F Service Manual page 36

LC-26GA5E
LC-26GA5E
LC-32GA5E
LC-32GA5E
Troubleshooting Table (continued)
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?
<Power supply Unit>
Are F701 and F702 normal?
Is F703 normal?
Is thermal fuse (F704) normal? (117°C specification)
Are the wire harness, FFC, etc. in the set connected properly?
Is a voltage of about 380 V applied to C709 and C710 when
power is turned on?
Is voltage generated at the +13V line (pin 1 of CN706)
immediately after supplying power?
Is +3.3V line (pins 11/12 of CN706) normal immediately after
supplying power?
Is F1001 (2.5A) of the Main PWB normal?
Is each REG-IC output normal?
(IC708 (4V), IC740 (33V), IC709 (5V), IC713 (12V), Q760 (6V))
Reconnect the power supply cord and turn on the power.
Replace F701 and F702, and then turn on the power. If a fuse
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.
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.
Reconnect the wire harness, FFC, etc. and check again.
Check the 380V system power supply circuit. (L703, IC701,
Q701~5, D705, TH701)
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?
Check the power supply circuit of the +3.3V line system.
(IC715, L715, T703, IC703, PC701-702) (F1001)
Check each REG-IC and each line.
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