820-3437 not turning on

[Gmorb]

The board is missing PP5V_S4RS3 and PM_SLP_S4_L is 0.064v i also notice that when the board is connected to a power supply it goes from 270amps then goes down to 60amps.

where should I begin.

 

[aprendiz]

what???? 270 amps??? 60 amps???

 

[Gmorb]

yes when connected to my benchtop power supply amperage is high then goes down seems like odd behavior not sure if that may be a clue to what could be wrong. it does look like the board has been worked on before seems like isl was replaced and a trace near the smc was blown re attached it. still nothing.

wondering if it could be smc related seeing how theres been damage around there.

 

[dukefawks]

With 270 Amps you can weld an inch thick steel. Please get your units right

 

[Gmorb]

0.260 amps
goes down to 0.060 amps

 

[dukefawks]

Board history? Is it power cycling on 5V_S4?

 

[Gmorb]

5v_s4 is present but not power cycling. it looks like it may have been water damaged before due to slight corrosion on test pads.

 

[dukefawks]

In the first post you said it was missing! What is it now?

 

[Gmorb]

sorry pp5v_s4rs3 is missing and not power cycling. pp5v_s4_ipd is present.

 

[dukefawks]

Crap under SMC is suspect. Checked PPVRTC too?

 

[Gmorb]

yes ppvrtc is present.

 

[dukefawks]

Reflow/reball SMC then.