Philips DVD590M Service Manual page 12

No supply at power on
Stand LED Light up
Not supply voltage output
when press power key
GO
Check point: PCON
Observe: Use an oscilloscope to
measure the PCON voltage output
jumps from0.7V to 0V.
YES
Check point: Measure Q306
Observe:? BASE terminal Q306 is 0V
? Collection terminal of Q306 is 5V
YES
Check point: Pin4 of Cn303
Observe: the voltage should be +5V
YES
Check point: L305
Observe: The waveform at Gate terminal is normal.
The pin4 of Cn303 is 5V.
YES
Check if VA+ VA- +2.5V are Ok
Solution: Replace Q302 Q303 U304 if damaged
4-2
Solution:
NO
Short PCON to GND and voltage
output restored Replace the CPU IC
on front panel
NO
Replace Q306
NO
Observe: Check D311
Solution: Replace if damaged
Trouble Shooting Chart