Got an 820-2936 board in that had no green light and ppbus_g3h measured out at 12.26v--"great--the SMC". I checked SMC_RESET_L and it's high, so I pulled the SMC. No liquid or corrosion or anything, so I figured it just died. Replaced the SMC and same behavior--no green light, ppbus_g3h is 12.26v and no shorts detected. I checked SMC_RESET_L again to be sure, and it's still present/steady, so I replaced U5110 to be safe. Still same behavior. I replaced U7000 because I've seen some odd behavior related to it failing before as well, but no dice--same behavior. Thinking maybe I grabbed a bad SMC, I swapped it a 2nd time. Same issue. Out of frustration, I replaced the SMC a third time (totally different chip pulled from parts boards both times I replaced it), and still the same behavior. I can't figure out what would be pulling ppbus_g3h down (no short) and preventing green light.
Any ideas? I thought for sure this was a bad SMC, but after replacing it 3 times and it not resolving the issue, there's clearly something else going on here. SMC_BC_ACOK at U7000 is 3.3v. No short on 3v42_g3h, and it's present/steady at 3.43v. This board had no liquid.
All help/direction appreciated!
Any ideas? I thought for sure this was a bad SMC, but after replacing it 3 times and it not resolving the issue, there's clearly something else going on here. SMC_BC_ACOK at U7000 is 3.3v. No short on 3v42_g3h, and it's present/steady at 3.43v. This board had no liquid.
All help/direction appreciated!
