820-4924 keyboard work just at the first 5 sec.

[yair37]

replaced motherboard.(was cpu dead board befor)
no water damage.
power button work
enter to boot menu.
succeed PRAM rese.
trackpad work.
trackpad number is 821-00721 i dont have another one, but when i put 821-00184 cable the keyboard full working but not the trackpad
what can it be??

 

[2informaticos]

So TP/KB work both good in boot menu, but in macOS TP doesn't work?
In such case, the problem is TP cable, or TP itself.
If both TP/KB not working in macOS, then you may have a problem with TPAD_SPI lines; check corresponding series resistors.

 

[yair37]

I will try to be more clearly.
With 821-00721 cable- TP fully working in boot menu and iOS.
KB work just for 5 sec(PARM work,enter boot menu work but not working it the boot menu an of course no in iOS !)
With 821-00184 cable- TP not working, not in boot menu and not on iOS.
KB full working in boot menu and in iOS.
I have just this 2 cables for checking
what lines can cause that maybe I can make jumper on the cable..

 

[2informaticos]

Be aware of new chinese cables.
I needed to test 3 one time, until found a good one.

Just in case, test known good trackpad board.