Chosen Solution
I have mid-2015 Macbook Pro Retina that is mostly non-responsive to keyboard input. The power button works fine and an SMC reset can be performed, but other than that there is no response to keyboard input. What has been tried so far: Tested with USB keyboard, it worksReset SMC and PRAM, no changeTested with new internal keyboard, does not workTested with new trackpad cable, no changeBooted to recovery mode, safe mode, ,single user mode and a test drive via USB, does not work in anyPasses Apple diagnostics test without error At this point I am pretty sure it s the logic board, but want to get some additional opinions. From what I have read, I understand the keyboard and trackpad somehow interact with each other despite having separate connectors on the logic board. However everything I have read indicates that if it were a problem tied to the trackpad then the trackpad should also be non-functional, but it isn’t. Any help would be greatly appreciated.
Forgot this was still hanging out there. In the end a replacement trackpad and cable fixed it.
I would suggest running Apple Diagnostics. Shut down the MacBookDisconnect everything except the chargerHold down the ‘D’ key, and boot the MacBookKeep holding the ‘D’ key until you are asked to select your languageOnce you select a language, Apple Diagnostics will run a bunch of tests If there is something wrong, you should get a reference code which may help you track down the issue. This could also potentially be a software issue, so if possible try a wipe and clean install. If your logic board is dead, you don’t have too much to lose.
Using your external keyboard go into the Keyboard system preferences and click on the Input tab remove the keyboard resource close the control panel and then reopen it and add it back in to refresh the resource using the plus key. Restart your system did that fix it?
I am having the same issue with my 2015 MacBook Pro. Keyboard replacement, powers on, can SMC reset, but no keys working in any OS
