Philips DVP3880K/55 Service Manual page 19

All output voltages on the power board is 0V or deviated.
All output voltages on
the power board is 0V or
deviated
Yes
Check whether
F1 is blown
No
Check whether there is
300V on C1 or C2.
Yes
Check whether 100KHz
oscillating signal
Pin6 of U20
Yes
Check if +5V and +12V are
short.
Yes
Check whether the components in the
short-circuit voltage are defected or eroded.
4-3
Yes
No
No
on
No
Replace F1
Replace C1&C2 if D1, D2, D3, D4 are
normal.
Check/ replace U20.
U1(PIN 3 - RC waveform)
Check whether U20 are eroded.
Trouble shooting chart
U1(PIN 8 - Drain waveform)