# Run A Hardware Check

If your Mac is behaving in an odd way, there may be an issue with some piece
of the hardware -- such as the RAM.

You can perform a hardware check in order to chase down a diagnosis.

- Shutdown your machine
- Boot your machine
- While it is booting, hold down the `d` key

At this point, the machine should have booted into a special hardware check
mode. Select your preferred language, the hardware check will be performed,
and any issues will be reported.

h/t Dillon Hafer