820-00165 no green light SMC_RESET_L present

[MexicoTV]

Hello all,

Am attempting to repair this board which has no green light. It has all the G3H "always present" voltage rails except that PPBUS_G3H is 8.1V. It is not going past this state and S4 and other voltages from there on out are missing. I can't see any shorts atm nor do i see an attempt at turning on and then shutting down because of a short. It just seems dead. SMC_RESET_L is 3.3v and the one wire circuit seems to be okay. I did have to cross ref the info for the LIO board where the one wire circuit is as I can't find the LIO schematic for this board.

Your help as always, greatly appreciated.

 

[JohnB8812]

Tried another DC-in board/cable? History liquid drop etc? Sounds like corrosion under the SMC or bad SMC to me

 

[MexicoTV]

Yes forgot to mention that I did try another DC in board and cable. Customer didnt mention liquid damage and I don't see any corrosion.

 

[JohnB8812]

Either corrosion under SMC, bad SMC, or bad ISL6259 (less likely). Start by giving the SMC a nice light reflow be sure to remove the edge bonding well. If no change, replace from and identical 820-00165 donor board.