Sharp Aquos LC-20S5U, Service Manual

Page: 30 / 77

LC-20S5U
30
TROUBLE SHOOTING TABLE
No
Yes
Yes
No
Yes
Yes
No
No
Is power cable properly connected to the main unit?
Connect the power cable properly, and turn on the power. Is there any faulty part or short-circuit in these line?
No
Is F7701 normal?
Replace F7701, turn on the power. If the fuse is still blown, replace VA7701, D7734 and repeat the check.
Yes
Remove the faulty part or short-circuit, and repeat the check.
No
Is SIG_VCC & INV_VCC line normal?
Yes
Reconnect the wire harness, FFC, etc. in the set, and repeat the check.
Check T7702 and its peripheral
Is pin (42) of IC2001 at "H"?
Check the line in question, IC2001 and its peripheral circuits.
Check the line in question, IC801 and its peripheral circuits.
Is pin (187) of IC801 at "H" or with pulse signal?
Check the built-in AC power unit, inverter unit and fluorescent lamp, and replace as required.
No video and audio output (no power supply)
Make sure the microprocessor's adjustment process menu settings are as specified.
Fluorescent lamp light-up failure