keyboard connector issue a1398

grmacs

Member
I replaced a keyboard connector on a1398 board and everything works except a couple keys: enter key, question mark, backslash, p, zero keys. I've zoomed in on pins and can see clearly no bridges on pins, all pins are solid to board and inside the connector the distances between the top and bottom pins are the same with door closed on the connector. Figured it must be the keyboard and tried a new keyboard and same keys are not working... could this be board trace on one of the pins?
 

grmacs

Member
tried reflowing j4813. will run a new trace if I can verify it's not there had to get different boardview.
Keys not working:
esc
f10
f11
zero
hyphen
p
backslash
colon
return
question mark
 

grmacs

Member
Also to note:
this runs slow unless in Safe Mode... almost like its getting inputs that arent there? theres often a lag between key press or mouse movement and visual change on screen. This mac had a liquid spill and when i got, however looked at it prior broke the keyboard connector and the fan connector. Board had been cleaned as there was no evidence of liquid visible.
 

2informaticos

Administrator
Staff member
I think my layout note is from an A1502 machine.
All mentioned keys are connected to pin 9 there.

Use a tweezer and make contacts between pin 9 and one of 10-12, 15-19, or 20-24.
If you get the above characters, then the problem is the connector.
Pins 11, 20, and 22 maybe don't generate anything (with pin 9).
 

grmacs

Member
It would've helped had I ran a trace to pin 9 and not pin 10!!!! Apparently I couldn't count to 9 yesterday. Keyboard works with jumper to pin 15 of u4820.
Something is scrambling this Mac though. As stated before it runs right on Safe Boot but regular boot there's a lag. Fresh install of Catalina. I tried booting off external El Capitan and same lag so it doesn't appear to be related to SSD.

Any suggestions? This had liquid damage but only noticeable evidence of that is red dot on battery and feedback from seller. Board had to have been at least cleaned. No noticeable residue. I believe the fan connector and keyboard connector were damaged by previous tech as prior owner said it worked some prior to taking it to repair shop. I assume then they broke the connector and then it appeared it was dead as the power button wouldn't have worked.
 
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