820-2936 cpu vcore stuck at 1.1V

Kyle93

Active member
Have a 820-2936 that had mild water damage. Board now turns on but cpuvcore hangs at 1.1V

What to check/ try first?
 

2informaticos

Administrator
Staff member
Where was the spill?
Try first other RAM, one module at a time.
Clean the memory slots and inspect their solders close to the edges.
Be sure R7402 has the correct value.
Check for corrosion around SPI chip U6100 and inspect all its traces and SPI termination resistors.
You can also try new BIOS.
 

Kyle93

Active member
Spill was just around lcd connector area.

Tried good ram one module at a time.

r7402 already has the correct value.

No corrosion around SPI u6100

Tried new bios and SMC but still same problem.

What to check next?
 

2informaticos

Administrator
Staff member
The PCH could got damaged by liquid.
Check all the lines which go from LCD connector to PCH; diode mode to ground.
Could also be a simple resistor, or even CPU.
Just in case, use good flux and heat PCH and CPU.
Be sure to get 25MHz from pin 9 of U2800.
 
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