820-3115 , from no power to power, then no power


New member
having a 820-3115 board, had liquid spilled on.
U7000 was bad and replaced. then ppbus_g3h came out.
it powered on but no back light, fixed that as well. then ran testings in OS.

found battery not being recognized. X mark,traced down to the SMC. and replaced it...

damn then the machine has no power on , green light is NOT there. check pp3v42 and ppbus g3h,which are fine.

then thought can be a bad SMC, replaced another two ... same story. then traced down and checked U6901.. pin 1 and 2 gets 2.8v.. pin 4 and pin5 are around 3.4-.3.4

doubting on pin 1 and pin2 . (2.8v), thinking should be around 3.3-3.4 as well.

any suggestion?

really don't think the SMC is the issue at this moment now, since replaced 3 times already( do this often and it's not from donor boards, from solid supplier . preprogramed SMC for this model..i actually just used the first one we tried to replace ,reballed and used on another board, and fixed that one, so pretty sure it's not the SMC)

thinking if anything around the SMC got heated up too much and got affected??

any suggestion or experience on this?

thank you


Super Moderator
Staff member
Make sure you have a connection between pin 1 of u6900 and pin 4 of u6901. Also, What is SYSONEWIRE and SMC BC ACOK VCC measuring? Also see if you have ADAPTER SENSE.


Super Moderator
Staff member
SMC BC ACOK is too low I believe. Check your soldering on U7000 and replace it again.... I seem to get some dud ISLs every now and then.


Staff member
Is R5087 corroded? This is under the heatsink so not visible if you are examining with heatsink on.

Is PPDCIN_G3H fluctuating between 16.6v to 16.1v rapidly on pin 1 or 2 of D7005?

Is PP5V1_CHGR_VDDP consistently present?