2015 15" Macbook 820-00426 a1398 - Trackpad issues

[mastak07]

Happy New Year guys!

I have a 15" MacBook with a trackpad that works when you press option/alt and choose the start up drive however once the Mac is booted into the OS the trackpad is unresponsive.

I changed trackpads and cables and no change. A couple of keys are not working as well, I have ordered a new keyboard.

Where do I start when problem solving this issue? I have seen an issue similar posted in here but I can't seem to find that post again.

Thankyou, Karl

 

[2informaticos]

Trackpad communicates with PCH through SPI bus, once logged into macOS.
If some keyboard keys still work then, the communication should be good; as keyboard codes ALWAYS go through trackpad to PCH.
Confirm your actual situation.

Use USB keyboard/trackpad and check the internal keyboard.

keyboard tester - Google Search

 

[mastak07]

Ok so I plugged in a USB keyboard and all the keys work. I replaced the trackpad+cable and the keyboard. The MacBook does the same thing. The trackpad works and all the keys on the replacement keyboard work before logging into the macOS.

After logging into macOS the trackpad stops working, Testing the keys on the keyboard once logged in and the keys 7,8,9,U,I,O,J,K,L,M, . do not work.

One thing I noticed testing the keys is when I click into the search bar top right to test keys, the letter i doesn't register on the on screen keyboard as clicking however it changes the window from the search bar at the top to a finder view and when |I press it again it reverts back to the search toolbar at the top of the screen.

So I guess my actual situation is logicboard issues not the trackpad or keyboard? Where to from here?

Thanks, K

 

[2informaticos]

The strange thing is that many keys still work once logged into macOS.

Check all RA294-99 resistors and traces.

 

[mastak07]

resistors and traces RA294-99 look ok

 

[mastak07]

Thanks for your help, I ended up creating a new user admin and this solved the issue.