820-00138 Fan Spin > Restart > High Fan

[820Slave]

I don't know where to start on this one.

I have the pdf but no bv. grrrr

green/amber charger
vcore, g3h, 342, present, warm processor

no backlight
no bootchime

fans spin up for 10 seconds or so, stop, spin up again to high fan. I don't know if that is the regular startup routine similar to 820-3437 etc.

coils above processor seem unusually warm, I could be mistaken.

Any leads would be appreciated.

 

[2informaticos]

Any history available?
Check for USB activity when board stays on.
You can try new BIOS, with clean ME; don't forget to save your backup...

 

[820Slave]

Oh man, sorry, yes Liquid damage. Bios seems really clean visually.

 

[2informaticos]

"yes Liquid damage"
Where was the spill?

 

[820Slave]

looks like a keyboard spill and some thru the back vent, corrosion near the keyboard backlit connector. board was run through the USC. Damn, sorry not providing important details.

 

[820Slave]

Need some momentum on this one, please help.

 

[820Slave]

No apparent USB activity.

1) USB Mouse will light up
2) USB Mem Stick with LED - NO access light. Verified Mem stick will blink on other Mac.

 

[2informaticos]

Post voltages for all big coils (secondary supplies).
Any reaction at pins 1, 7, 3 of U1950?

 

[SMMRepair]

CPU power supply circuit getting hot + liquid through back vents and to KBD BL conn. (right by S5_HS) + high-fans/no chime = dead CPU. You can confirm by checking all the usuals, but this one's going to be dead.

 

[820Slave]

As soon as I touched the coils that was my thinking, just needed another brain to confirm. thx.