Macbook 820-3437 Not Turning ON

[Instafixx]

Drawing only 28 Amps.
PPBUS is 8.6V
PP3v43 is 3.4V
U1900 was mildly heating up.
Replaced it. Still the same.
PP3v3_s5 is 0.065 Diode to ground
RTC Pull up resistors line are shorted .

BAD U1900?

 

[2informaticos]

I don't think, once you've replaced it.
Possibly leaky cap.

 

[Instafixx]

Removed all caps and even the U1900 just in case. Still it's shorted. CPU gone ?

 

[2informaticos]

You can't heat anything injecting voltage there.
However, a good thermal camera can show you very small temperature differences.
Injecting until 4V into 3V3_S5 shouldn't cause any damage.
Remove CPU heatsink first.

 

[Instafixx]

Injecting voltage in 3v3_s5 ? RTC Pull up line PPVRTC_G3H is shorted

 

[2informaticos]

"PP3v3_s5 is 0.065 Diode to ground"
Normal reading after U1900 was replaced?

"PPVRTC_G3H is shorted"
If pure short, start injecting with 1V.