Apple gives you a number of options if you need to troubleshoot software and hardware issues that might be plaguing your Mac. If you cannot determine the root cause of your problem by isolating issues in macOS, your first port of call should be macOS' built-in recovery tools.
But that may not be necessarily enough and Recovery Mode may be unable to help you get your Mac back to working order.
As the last option, you can boot your Mac in a hardware diagnostics mode, which on newer Macs is called Apple Diagnostics or Apple Hardware Test on older models. In this tutorial, we'll show you how to enter Apple Diagnostics or Apple Hardware Test mode to identify the potential source of a hardware issue.