820-3476 No Post or USB activity

[tlough75]

I have on the bench and 820-3476 that has Magsafe light, PPBUS_G3H is 12.57V, CPU gets hot but no USB activity or Chime/Image. This unit did suffer a water spill and the noted areas of corrosion are In the U7200 area. I replaced U7200 but no change. I am getting ALL_SYS_PWRGD so I assume all rails are present.

 

[2informaticos]

If CPU gets hot, probably VCORE is present.
But do NOT assume; check if is there.
If present, try known good BIOS.

U7200 is CPU VCORE power supply controller.
You can also try changing C1031.

 

[tlough75]

Ok, i'll check that. Ithiought I checked a few days ago and founf that it has VCORE but I will double check.