Using Apple Hardware Test on your MacBook, iMac or Mac Pro

Back in the good ol’ days, if you wanted to find out if you had a hardware fault with a Mac, you need to use the Apple Hardware Test CD that came with your Mac, or use the restricted Apple Service Tools. However, with more modern Intel based Macs, Apple have used some of the space in the “Firmware” Boot ROM to stick the test tool directly onto the Mac.

If you hold down F2 on startup, you may, depending on your model, be able to start the hardware tests. Typically they won’t find anything, unless you enable test looping (Apple + L) and leave it running for a few days, but it’s worth a quick look.

A customer in Bath had a problem with it intermittently failing to boot; which could point to a failing MacBook hard drive. I replaced the drive, copied their data onto the new drive and took a Time Machine backup. However I couldn’t find any evidence in the system.log of disk I/O errors, so a quick trip into the hardware tests was called for, which also revealed nothing…