820-3437 Quarter Fan Spin - Does Not Turn On

mccafe

Member
Hello guys,

I have here a troubled 820-3437 board. When plugging in the original adaptor, the fan would do a quarter spin. All G3H rails are good. It would go to S0 state for a split second and then drops.

U8080:
- PP5V_S4RS3 would go to 5V and then goes to 0
- P5VS0_EN would also go to 5V and then goes to 0

No history of water damage, but a lot of dust near the edge of the board. Some points look dirty, but I do not think any are corroded (I could be wrong).

Any advice?

Thanks
 
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mccafe

Member
CPU Vcore would go to 1.7 volts and then to 0. I'd like to clarify that the voltages are measured for a split second and would go to and stay at 0 until I replug the power adaptor.
 

dukefawks

Administrator
If CPU Vcore is also pulsing just like the fan it could be pretty much anything. The usual suspects in case of liquid would be U1900,1950 and the U6100 area. If you are 1000% positive it is not liquid it could be a corrupt BIOS. You should see if there is any more history to this machine, a drop maybe, something plugged in and it died?
 

mccafe

Member
Thanks.

I ultra-sonically cleaned it and when I first plugged in the adaptor, green/red light and no fan spin. Replugged it in and no more light. Sometimes if I leave the adaptor in it would go green/red after like 20-30 seconds which is odd. What could be the cause of this?

I will test the traces in the U6100 and U1950 areas.

EDIT: I lied. Green/red light is good now. I probably didn't leave it submerged in alcohol long enough after the ultra-sonic cleaning to get all the water out. But still no fan spin.
 
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