[SOLVED]A1398 820-3662 liquid spilled, restored power but no post.

roy.ruan

New member
Having this 820-3662 board. liquid spilled around led connector, u7501 area.

no power.
fixed u7501 area, and power on,fan spins. but no video.( no chime sound)

check back light circuit,nothing on l8300.

checked CPU vcore and it's there.

connector got replaced with new one already.

any advice?
 

roy.ruan

New member
yes both , no video at all. not back light issue.
Checked with a DC power supply,compare with good board.

good board should jump from 0.01 to 1.4 AMP after boot up.
this one only goes to 0.4A then stop, looks like some voltage is not coming out, but checked all big coil , they all exist already. even CPU vcore comes out already.
 

dukefawks

Administrator
Pretty much out of options here. Check closely for more corrosion again, especially U6100, clock, U1950, SMC. If all ok then could still be dead CPU.
 

roy.ruan

New member
I poled around and compared with the good board, found one thing can be the hint.

diode mode on pp3v3_s0, only gets 0.035
the good one is around 0.319

but when powers on, pp3v3_s0 is 3.3v still , doesn't look like pulling down. something shorted?
 

dukefawks

Administrator
That is indeed way too low. That is also a rail that has pretty much everything connected to it. Maybe inject 3V there and see if anything warms up.
 

roy.ruan

New member
removed r7640, diode mode 0 on its pin 1.

damn.turn out to be one of the shits I never wanted to do. it's a dead PCH.

it's SR17D,having one last piece here, will do the BGA replacement and update back
 

roy.ruan

New member
HAHA, it's my lucky day. replaced the PCH, power up and took a while to post.

knowing it's the ME issue, flashed the bios with cleaned me file. all boots up and works now!!

thanks for the advice guys!
 
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