Apple MacBook Pro Logic Board 820-2936-B

[mferna14]

Hi, Working on a Apple MacBook Pro Logic Board 820-2936-B. Symptoms was it turns on, fan spins & then shuts off ater a minute, after a second it turns on again & then off again after 1 min & this happens till the Magsafe power is attached. After a microscopic inspection, I saw liquid spill & Corrosion on Q3210. I replaced with another one & checked the circuits were all intact & did a cleaning on the nearby components. But the problem presists. Now I noticed when I remove both the memory chips all voltages are back & the fan spin is good & does not shut on & off. As soon as the memory is installed in either slot, logic board goes on & off status same as before. Can anyone help me from where to start troubleshooting. Thanks

[mnciks11]

Re: Apple MacBook Pro Logic Board 820-2936-B

I’m facing such issue on the windows laptop, it does the same issue, without ram installed it doesn’t shut down but as soon as i put the ram it turns on and quickly shuts down

[mnciks11]

Re: Apple MacBook Pro Logic Board 820-2936-B

Have you checked for shorts to ground on all power supplies?

[piernov]

Re: Apple MacBook Pro Logic Board 820-2936-B

Tried PRAM reset?
Does it chime?
Does it have image?
If you plug in a USB drive does its activity LED blink?

[mferna14]

Re: Apple MacBook Pro Logic Board 820-2936-B

Tried PRAM reset? Done... Does not turn on for long, but still I held on the 4 keys, nothing happens
Does it chime? No Chime at all... fan moves for a while & then shuts down. I measured that 5V rail just disappears but 3.3v railis always present, automatically the 5v rail turns on again & then shuts down again
Does it have image? No image at all
If you plug in a USB drive does its activity LED blink? USB plugged in but nothing happens
I do not see any shorts to ground. But all the BGA chip are getting hot. Where can the problem be... Just wondering...