hp 450 g4 motherboard problem

[Normunds]

19 volts on fet drain, but nothing on source or gate, no shorts to ground on any coils, looked at power management chip and not getting 25v on acdrv. at power connector i am using labaratory power supply 19v and resistor of 100 ohm to 6th leg for ad_id signal. pwm chip: vcc- 18,82v ac det- 2,59v regn- 5.99
link to boardwiew schematics etc https://failiem.lv/u/n9ah9h829

[Techtiger]

Re: hp 450 g4 motherboard problem

Does this MB have 2 fets PQ26 PQ27 check the resistance first DSG , you should have 2caps & 1 résister on that line test for any short ? What is the resistance on +PRWSRC ?

[Stevedb]

Re: hp 450 g4 motherboard problem

Check if the first or second mosfet is shorted on ohms mode scale 200 must be all open line.

Good luck

Steve