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Is this a 2012? If so I would look at a schematic for a fan circuit on a macbook board and see if you see any resemblance... That's if the fan is the issue.. Troubleshooting without a schematic is going to be a tough one.
I've had onewire and Adapter sense be the same 3.4 v and U6900 was bad... When I was troubleshooting this board I replaced u6900 from one I had on my mat... now that I think about it, that u6900 that I used may have been a bad one
I've had a board with the same adapter sense and onewire readings before.... u6900 is bad... And of course it's stolen off all my donors... More on the way thogh
jgraffis I know you didn't want me to reball it, But I wanted to do it just to rule out if there was crap under it... The voltage was the same on SMC_BC_ACOK_VCC with u6900 removed ,I forgot to include that in the above post.
dukefawks OK... I have restored PPBUS. However, Still no green light.. I'm thinking bad SMC or u6900...
Adapter Sense = 1.09v
Sys One wire is jumping between .30 and .75 v
SMC BC ACOK _VCC is 0.13 v
SMC BC ACOK is 3.21 v
PPBUS_G3H is 12.23v So the SMC is on?
PP3v42 is 3.42v ....
So right...
gcain Check your clock circuit.... If everything looks and measures ok leading to u1900, I would take the long shot and replace the chip... Takes 2 min and It will rule out the possibility of a bad clock chip...
It's a VRAM chip failing.... It works again after it sits because the VRAM had a chance to cool down... Kinda like how some failing graphics chips crash after rising above a certain temp... The resistance is higher in a hot chip then a cold chip so once it gets hot enough, the part of the die...
However, Since Pm_SLP_S4_L is missing, Those resistors are not likely the cause of the problem, but they need to be checked.... PM_SLP_S4_L comes from the CPU, But can't be generated if the CPU isn't on or if the clock signal is messed up. Check your clock circuit and see if you have Vcore.