[DEAD]820-3437 No turn on, PPVCC_S0_CPU I believe

[G.Beard]

PPBUS_G3H = 8V6
PP3V42_G3H = 3V44
PPVRTC_G3H = 3V3
PP5V_S5 = 5V
PP3V3_S5 = 3V3


PP3V3_S0 = 61mV
PP5V_S0 = 0V


PPVCC_S0_CPU = 0V -> 0.5 Ohms to ground

Removed R7310 and R7320 tested each pad.
R7320 Pad 2 (PPVCC_S0_CPU) / R7310 Pad 1 (PPVCC_S0_CPU) = 0.5 Ohms to ground.
Injected 1V but it only pulls ~ 1A and voltage not pulled to 0 and maintains at 1V. Clearly, nothing is going to get hot...... Is it possible CPU or bad cap or am I completely wrong?

What should I do please?

 

[dukefawks]

First off, was this liquid and where?

 

[G.Beard]

Yes liquid damage around U1900, U6100, Y1915, U3540.

L7310, L7320 look a little brown

Board had been cleaned before it was sent.

 

[dukefawks]

Replace U1900 and check resistors in data lines and the traces to U6100.

 

[G.Beard]

Replace U1900 and check resistors in data lines and the traces to U6100.

No change. R values good, traces good.

Resistance to ground on PPVCC_S0_CPU = 0.5Ohms.

 

[dukefawks]

Measured on a good board here CPU Vcore is about 140 Ohms. I think your CPU is cooked.

 

[G.Beard]

I thought you may say that. Good board most certainly NOT 0.5ohms......

A moment of silence for my dead CPU please.