PHILIPS DVD590M
Service Manual

4-8 Trouble Shooting Chart Microphone not working
No voice from Microphone

GO YES
Check point: the Q503 on power board Observe: check the collector terminal voltage is over+0v7

Solution: replace the transistor

NO

Check point: Q503 on power board Observe: check the collector

YES Solution: Replace Q503

terminal is short circuit to ground

NO NO
Solution: check the +5V supply Circuit replaces any defected components

Check the +5V is presented

YES

Check point: Microphone input Observe: check if the any signal presenting at pin7 of CON601 by

YES

Solution: replace U601 on echo board if no signal output from pin 15

NO NO
Check point: VA+ and VA- on microphone board Observe: heck if the supply

Solution: check the connector between echo board and microphone

voltage is +/-10V

YES
Solution: replace the U401 on microphone board