Sharp Aquos LC-37D90U, Service Manual

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LC-37D90U
6 – 1
LC-37D90U
Service Manual
CHAPTER 6.
TROUBLE SHOOTING TABLE
[1] TROUBLE SHOOTING TABLE
<Power Supply>
No power supply (Front LED does not light up) and no power-up even if turned on(Front LED light up to green)
Is the AC power cord plugged in?
NO
Plug in the AC power cord and turn on the power.
YES
Are the harnesses and FFCs tightly connected?
NO
Connect the harnesses and FFCs tightly.
YES
Does F701 function?
NO
Replace F701 with new one and turn on the power. If the fuse blows out
again, replace the following parts with new ones and check the fuse
again: VZ701, DS4701, F4701, F4702, F5701, Q4701, Q4702, Q5701,
IC4701 and IC5701.
YES
Is there a voltage of about 160V at C4701, C4702 and
C4703?
NO
See if VZ701, R701, R702, R703, DS4701 and TH701 function.
YES
Is there the BU5V output?
NO
Do the primary and secondary sides of T5701 oscillate as specified?
YES NO
Check F5702, D5705, IC5706 and
D5717 for defects. Check the primary-side parts
for defects. See if the second-
ary output is short-circuited.
YES
Are there the UR6V, UR10V and UR13V outputs?
NO
Is PS_ON (pin (1) of CN5702) at High (about 3.3V)?
YES NO
Check the UR6V regulator circuit,
UR13V rectifier circuit and UR10V
DC/DC circuit. Make sure the set is not in
STANDBY MODE2. Check the
main unit for trouble.
YES
Is there the 24V output?
NO
Do the primary and secondary sides of T4701 oscillate as specified?
YES NO