My computer is a mid-2014 retina MacBook Pro.
After five days of sleep, the trackpad stopped responding to touch input, and couldn’t be revived by any number of NVRAM/PRAM/SMC resets. Most recently, the keyboard has also started to become unresponsive after waking from sleep until the computer is rebooted. No water damage occurred.
I have access to some spare parts due to trackpad cable shenanigans from days past:
- 2x iFixit trackpad (excluding cables),
- 1x iFixit trackpad cable, and
- 1x original Apple trackpad cable (known defective)
For clarification, in my attempts below, I refer to the Apple trackpad and cable as “original”, the two iFixit trackpads as trackpads “A” and “B”, and the iFixit trackpad cables as “1” and “2”.
The setup currently operating inside the MBP comprises iFixit trackpad cable “A” and the original Apple trackpad.
I’ve tried the following things, to no avail:
- NVRAM/PRAM reset
- SMC reset (NVRAM/PRAM/SMC were reset multiple times now and after almost every later step)
- Checked that trackpad is still recognized under System Information – still there, from previous experience if the trackpad isn’t detected it doesn’t show up in here
- Deleted trackpad preferences
- Tried updating software to latest version – macOS Catalina 10.15.6
diskutil verifyVolume and
- Tried booting into Recovery to isolate if issue is software or hardware related – seems to be hardware related since the issue persists in Recovery
- Ran Diagnostic Test to see if any issues with trackpad were reported – no issues were found
- Tried booting into external boot drive to isolate if issue is software or hardware related – issue persists
- Tried original trackpad with original cable – this is a known defective combo, which gave me trackpad issues last year with wild inputs; no inputs were detected this time around
- Tried original trackpad with iFixit cable A
- Tried original trackpad with iFixit cable B
- Tried iFixit trackpad A with original cable
- Tried iFixit trackpad A with iFixit cable A
- Tried iFixit trackpad A with iFixit cable B
- Tried iFixit trackpad B with original cable
- Tried iFixit trackpad B with iFixit cable A
- Tried iFixit trackpad B with iFixit cable B
- Debugged in Single User Mode and saw errors arising from AppleUSBMultitouch saying
(HID) (USBMT) (Error) ReportID is invalid in AppleUSBMultitouchDriver::_deviceGetReportWithLookup – I doubt this is the issue, since it should be driven by
AppleMultitouchDriver; but as the trackpad is classified as a USB device under System Preferences, I wasn’t too sure
- Booted into Recovery and saw that the error message mentioned above did not appear, arousing suspicion it is software related – again, I’m not sure if this is the issue; even though the error message didn’t appear the issue persisted
- Tried replacing
AppleTopCase kernel extensions with fresh kernel extensions from macOS installer – didn’t work because codesign is different
- Tried macOS 10.15.6 reinstall – also didn’t work, but the error mentioned in (20) was no longer present
- Tried fresh macOS install on a brand new partition – no luck here either
- Procured replacement iFixit trackpad cable, and tested with original trackpad – this was done on the suspicion that all my cables may be defective
- Tested replacement cable with trackpad A – didn’t work
- Tested replacement cable with trackpad B – didn’t work
- Reseated trackpad and keyboard cables fully – didn’t work
- Removed logic board to inspect CY8C24794-24LTXI USB controller connections for corrosion – I live in an area near the ocean where corrosion of metallic parts is inevitable after a few years, so I figured that might’ve been an unfortunate cause. However upon close inspection with a microscope looking for signs of corrosion, dejointing, or shorts no glaring issues were found with the chip or its joints. The ZIF connectors were also in good shape.
I’ve also taken it to an Apple Genius, but they ran their tests, found nothing wrong, and told me I’ve already done pretty much what they would’ve done, if not more. This leaves me quite stuck with truly no idea what’s going on with my trackpad and keyboard subsystem. For now, I’ve started using the ol’ wireless mouse (and sometimes keyboard), and that should tide me through for a while.
Are there any possible causes of this issue, or perhaps solutions to reviving the trackpad?