[SOLVED] 820-3023 Fan spins for 1 second, stops and repeats

[No-Clean]

All rails present, rails after PP5V_S5 pulse as the fan turns on, clean board, no RAM beeps, customer states that it just stopped working.

 

[2informaticos]

ALL_SYS_PWRGD pulses too?
Also check for pulse at CPU coils; as other big coils too.

Inspect U2750/60 and post voltages and pulses at their pins.

Check all power rails from pages 60/61.

 

[No-Clean]

Yes ALL_SYS_PWRGD pulses too
Not all the big coils pulse

U2750 pin5 3.3v, pin4 0v, pin2 pulses below 0v, pin1 pulses 3.3v to 0v
U2760 pin5 3.3v, pin4 0v, pin2 pulses 3.3v tp 0v, pin1 0v
Power Rails
ppbus 8.39v
PP3V42_G3H 3.4v
PP5V_S5 5v
PP5V_S3 pulses 5v to 0v
PP5V_S0 pulses 5v to 0v
PP3V3_S5 3.3v
PP3V3_SUS 3.3v
PP3V3_S3 pulses
PP3V3_S0 pulses
PP1V8_S0 pulses
​

 

[2informaticos]

So no pulse at all at L7510/50?
Check if R7402 is good.
You can try known good working BIOS, just for test.

 

[No-Clean]

Correct, no pulse on L7510/50, R7402 is good at 90k, I will try to get good BIOS

 

[No-Clean]

New BIOS did it, thanks!!!! One board at least!