19V problem, Please i need help from expart.

[nazrul145]

Dear friend, i have problem with this motherboard. It has no power from adapter.
I have check PQ25 pin4 has 18.8V, But no Pin3 +pwrsrc =4.6v, and pin1=5V.
I have check pr173. Its input=28v but output=5v.
I think PQ25 pin1 voltage needs high for output 19v.
Please i want hep from expert.
Pleease help me, Thanks advance.

[nazrul145]

Re: 19V problem, Please i need help from expart.

Schematic here.

[dycc]

Re: 19V problem, Please i need help from expart.

PQ3 mosfet p channel is the problem . remove it and you must get 19v on pin 3 pq25(without pq3). if all is OK replace PQ3 with a good working p channel mosfet

[khaahk]

Re: 19V problem, Please i need help from expart.

Check these values also:
PU3 pin 1 VIN
PU3 pin 9 ACAV
PQ27 pin2 ACOK#

[nazrul145]

Re: 19V problem, Please i need help from expart.

Thanks lot everyone speacially dycc. Problem was PQ3 and replaced now ok.