Was hoping this would be a U5110/SMC/J9500 issue, but it's not proving to be that simple.
This board came from a customer unit that was an Apple refurbished piece of garbage, and the board failed in the unit. I notice the board has been repaired from significant liquid in the past (repairs look old, covered in dust, etc), but the symptoms are confusing me:
1. PPBUS was 8.17v and no green light; no shorts on ppbus or 3v42. I checked U5110 and then moved onto replacing the SMC.
2. Replaced SMC, and issues persist.
3. I inspected J9500 very, very well, and no issues found.
4. Replaced SMC again, issue remains.
5. Measurements at U5110 are all correct and steady.
I'm not sure what else to check at this point. Unit does not power on from battery either. No green light after 2 SMCs, no shorts. Known-good DC-In/cable (3). Any ideas? Am I missing something "further up" in the power-on sequence? Not having the proper block diagram makes it harder for me on these boards. All help appreciated.
This board came from a customer unit that was an Apple refurbished piece of garbage, and the board failed in the unit. I notice the board has been repaired from significant liquid in the past (repairs look old, covered in dust, etc), but the symptoms are confusing me:
1. PPBUS was 8.17v and no green light; no shorts on ppbus or 3v42. I checked U5110 and then moved onto replacing the SMC.
2. Replaced SMC, and issues persist.
3. I inspected J9500 very, very well, and no issues found.
4. Replaced SMC again, issue remains.
5. Measurements at U5110 are all correct and steady.
I'm not sure what else to check at this point. Unit does not power on from battery either. No green light after 2 SMCs, no shorts. Known-good DC-In/cable (3). Any ideas? Am I missing something "further up" in the power-on sequence? Not having the proper block diagram makes it harder for me on these boards. All help appreciated.
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