820-00875 pp3v3_S5 is shorted

[Don Anton]

Hi,

This is not a liquid damaged board but U3100 and U3200 both blown and no power at all. I replaced both chips and now I get 20v in SUBC_VBUS , 13v ppbus_g3h ,3.3v PP3v3_GH3.

Then PP5v_s5,PP3v3_s5, p5VP3V3_VREF pulisng and not stable. then became 0V on pp5v_s5, pp3v3_S5 and PP3v3_s5 in shorted and 0v on diod mode.

I injected 3.3v to pp3v3_S5 and heating component are U7800 and PCH. I replaced the U7800 and still the short is there.

Any adivce will be greatly appriciated.

Regards

Don

 

[JohnB8812]

I think you know what's dead here unfortunately...

 

[2informaticos]

If now only PCH/CPU heats up, can't doubt anymore...

 

[Don Anton]

I doubt about a dead PCH. but as more than 10 line of PP3V3_S5G goes straight tothe PCH I'm doubting is it normail to get PCH hot when I inject 3.3v on line line.

 

[Don Anton]

Hi Duke,

really appriciate you advice/opinion in regards this. thank you.

 

[2informaticos]

If PCH heats when inhect into one of its 3V3 lines, this very clear; dead PCH...
A good PCH cannot sink more than some tens, or hundreds mA, depending where the voltage is injected.
That cannot make it hot at all.