820-4924 Shuts off if Track Pad is connected

820-4924 came in for liquid spill.

Opened it up and pulled the board. The board looks almost new. The water indicator is red but the board has no corrosion and very little signs of liquid present.

Cleaned what little liquid residue I could fine. Put it together it works but battery is shot.

Replace battery and computer starts turning itself off on boot. As soon as logo comes up 2 seconds later it shuts off. Disconnect track pad and the computer stays on. So track pad must be faulty?

Replace track pad and cable and it does the same thing.

What am I missing? Is track pad connected causing something odd with the keyboard? I looked at the connectors and the board and can see no indication of what may be messed up.
 

SMMRepair

Member
Did you replace the trackpad and cable with KNOWN-GOOD parts? Also, confirm it isn't cutting off because of a faulty SSD as well. Boot into verbose mode and see where it cuts off or hangs up.
 
Im live streaming now of what its doing Duke if youd like to see.

If I plug in the track pad it will boot for 2-3 seconds like chime then backlight then turns off. I cant even get to a menu to see if it works
 
So to recap it will boot if

Keyboard plugged in track pad not
Track Pad plugged in Keyboard not

If both plugged in it will boot then shut off in 2-3 seconds from chime
 
I dont have a spare here. Ive ordered it but the thing that I don't understand and maybe you can explain it Duke.

If the keyboard is bad why does the PC boot and not turn itself off when the keyboard only is plugged in and the power button functions normally.

I noticed while probing the SMC_ONOFF_L rail with just the keyboard or just the track pad the line stays high 3.3v but if I connect the track pad and keyboard the line goes low .667v. My logic on it is if the SMC_ONOFF_L comes from the power button shouldnt it do that with just the keyboard plugged in also?
 

dukefawks

Administrator
Keyboard loops through the trackpad. You can connect any macbook keyboard, the pinouts are all the same.
 
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