Chosen Solution

Here’s a strange one for you guys. I just picked up a used MacBook that I’m working on refurbishing for sale. The trackpad needed to be replaced, so I took care of that. I also upgraded the hard drive and RAM (came with 2 GB upgraded to 4 GB). After all that was done, I went to format the HD and install a fresh copy of Mavericks. Strangely enough though, my usual method of holding down the option key at startup so I can select my Mavericks USB install drive did not work. When I tried, it just booted up normally. So I changed the startup disk in System Preferences and did the format and install figuring that maybe the problem would resolve itself with a fresh copy of OS X. Unfortunately it did not. I tried to reset the PRAM, and discovered that I am not able to do that either. In fact, when resetting the PRAM, it boots into recovery mode, so it is at least recognizing that I have the R key held down. At this point, I started to explore the idea that the keyboard could be faulty. I first tried to use an external keyboard and saw no changes in behavior. Then I booted the machine and tested each key. No issues with any of the keys responding. So I don’t believe that it’s the keyboard. Other troubleshooting that I have done:

  • Checked to see if there was a firmware password set, There was not. I enabled a firmware password, rebooted, and removed it just to be sure that it was off.
  • I tried installing the original RAM that came with the machine. No changes.
  • I tried installing other RAM, both 1 and 2 GB SODIMM’s, again, no luck. So anyone have any suggestions? If it’s not the keyboard, there isn’t a firmware password, and it’s not the RAM, what in the world could be causing this?? Thanks!

I would remove the target HDD from the case, put it in an enclosure, plug it into my MacBook Pro, then examine it using Disk Utility. I’d look for odd partitions for example, the sort some people cause when they install Windows on a Mac using 3rd party software instead of Boot Camp, or partition the HDD from Boot Camp, etc. that could be causing issues at the HDD level. At this point, it would be possible to verify/repair and plug back into the old Mac. But why bother? I’d format it and restore a working OS from the source HDD plugged into another USB. Then run verify/repair and permissions to check everything is ok. Then install in the old Mac, restart, and test. That’s my thought..

Yes, very odd… How about checking the firmware. Follow this Apple TN: EFI and SMC firmware updates for Intel-based Macs.