Chapter 6. Trouble Shooting Table; Trouble Shooting Table - Sharp LC-37D90U Service Manual

LC-37D90U
CHAPTER 6.
LC-37D90U

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?
Are the harnesses and FFCs tightly connected?
Does F701 function?
Is there a voltage of about 160V at C4701, C4702 and
C4703?
Is there the BU5V output?
Are there the UR6V, UR10V and UR13V outputs?
Is there the 24V output?
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
Service Manual
Plug in the AC power cord and turn on the power.
Connect the harnesses and FFCs tightly.
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.
See if VZ701, R701, R702, R703, DS4701 and TH701 function.
Do the primary and secondary sides of T5701 oscillate as specified?
YES
Check F5702, D5705, IC5706 and
D5717 for defects.
Is PS_ON (pin (1) of CN5702) at High (about 3.3V)?
YES
Check the UR6V regulator circuit,
UR13V rectifier circuit and UR10V
DC/DC circuit.
Do the primary and secondary sides of T4701 oscillate as specified?
YES
6 – 1
NO
Check the primary-side parts
for defects. See if the second-
ary output is short-circuited.
NO
Make sure the set is not in
STANDBY MODE2. Check the
main unit for trouble.
NO