Apple has a built-in tool to check for hardware failures that you can run in minutes. Shut down the Mac.
The screen is the most expensive part of an iMac to replace. buying used imac tips
Turn it on and immediately press and hold the (for Intel) or hold the Power button until "Loading startup options" appears (for Apple Silicon). Apple has a built-in tool to check for
Run your fingernail along the edges of the glass to feel for small cracks. walk away. 6. Run Apple Diagnostics
iMacs are "all-in-one" units, so a dead port usually means a dead motherboard.
Ideally, you should see the "Hello" setup screen. If the Mac boots straight to a desktop with a password you don't know, walk away. 6. Run Apple Diagnostics