4-3
All output voltages on the power board is 0V or deviated.
No
No
No
Yes
No
U1(PIN 4 - Drain waveform)
Replace F501
Replace C501&C502 if D501, D502,
D503, D504 are normal.
Check/ replace U1.
Check whether U1 are eroded.
All output voltages on
the power board is 0V or
deviated
Check whether there is
300V on C501 or C502.
Check whether 100KHz
oscillating signal on
Pin4 of U1
Check if +5V and +12V are
short.
Check whether the components in the
short-circuit voltage are defected or eroded.
Yes
Yes
Yes
Yes
Trouble shooting chart
Check whether
F 501 is blown