Power Board - LiteOn B17AAU Service Manual

12. Power Board

Trouble Shooting
Check output voltage +5V, +12V is
right or not.
Yes
No It is not power board problem
Check power switch is turn on or not.
No
Yes
Check power cord (P801), Signal cable (P302),
P802, P803, CN102, CN103 is connected right or not.
No
Yes
Check C805 is about DC140V~330V
or not.
No
Yes Check F801, D801, P801 and repair them.
Check C807 is over 10V or not.
No
Yes Check R805, R803, I801 and repair them.
Check pin 6 of I801 have same
pulse or not.
Check peripheral components of I801 and repair
No
Yes
Check pin 1 of T802 have same
pulse or not.
Check Q803, R813, R814, D806, R812 and
No
Yes
Check peak voltage of R811 triangle
pulse is up to 1 volt or not.
No
Yes Check D804, R807 and repair them.
Check D809, D810, C816, C821, T802 have same
short circuit, or the output +5V, +15V is over load.
No
Yes
Check feedback circuit around I802, I803 and the
other components and repair them.
B17AAU / B17ANU / B17AAY
Turn switch on.
Connect it right
them.
repair them.
Repair them
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