Philips MDV460 Service Manual page 13

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 and C2.
Yes
Check whether 100KHz
oscillating
Pin6 of U1
Yes
Check if +5V, , +12V and
-12V are short.
Yes
Check whether the components in the
short-circuit voltage are defected or eroded.
Yes
No
signal on
4-3
Replace F1
Replace C1&C2 if D1, D2, D3, D4 are
normal.
No
Check/ replace U1.
U1(PIN 3 - RC waveform)
No
Check whether U1 are eroded.
T rouble shooting chart
U1(PIN 8 - Drain waveform)