2915 no power on 5v_s3 and s0

[nate8organic]

got a 2915 board. no power, replaced lots of parts so far, was missing pp5v and pp5v sus, brought it back replaced the q7802. tracking down the 5v_s3 and traced it back to the PM_SLP_S4_L has no power. I seem to be getting lost trying to track down the power creation for 5v_s3 any help is greatly appreciated.

 

[dukefawks]

Why lots of parts replaced? Why was Q7802 dead, does usually not just happen. Liquid damage?

 

[nate8organic]

Yes, Sorry should have mentioned that it was very badly liquid damaged. some fried stuff and stuff that did not look good. idk not that much in general just more than normal replaced. pretty toasted board to start with. normally i would just toss it and move on. but i have some extra time and want to keep learning more so taking the time to go through everything here and understand it all better. q7802 was dead from bad liquid around that areas along with some other parts on that rail that looked fried.

 

[dukefawks]

Well then it could be anything. Corrosion under SMC/PCH etc. Check RTC voltages and 32KHz from clock chip.