Whichever you are going to run, prepare your Mac first by: Apple’s instructions are here for Macs released before June 2013, which run Apple Hardware Test, and here for newer Macs, which run Apple Diagnostics. Insert the labelled disk into their optical drive, restart from that, and follow the instructions.Īll more recent models can be started up in diagnostic mode, by holding down the D key.
Older Macs may still need their original install (optical) disk(s), which contain their diagnostic software. If you think your Mac has a hardware problem, or want to rule that out, they provide the best way of checking.
All recent models of Mac contain built-in hardware diagnostics, known as either Apple Hardware Test or Apple Diagnostics, according to the model.
