Bring a USB drive and a pair of headphones to test every single port on the back.
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 buying used imac tips
Apple has a built-in tool to check for hardware failures that you can run in minutes. Shut down the Mac. Bring a USB drive and a pair of
The tool will run and give you a reference code. If it says "No issues found," you're in the clear. The tool will run and give you a reference code
If buying in person, run Disk Utility (Command + Space, type "Disk Utility") to ensure the drive status is "Healthy." 4. Test the Ports and Peripherals
A mechanical hard drive will make even a powerful iMac feel painfully slow. According to testing from Macworld , an SSD-equipped Mac can be up to 10x faster in everyday tasks than one with a traditional hard drive.