Troubleshooting Methodology

POST Beep Codes

One or no beep indicates that all is well after POST. However, startup BIOS/
UEFI communicates POST errors as a series of beeps before it tests video.
Search the website of the motherboard or BIOS/UEFI manufacturer to know
how to interpret a series of beep codes. You might need to restart the system
more than once so you can carefully count the beeps.

Windows STOP Errors – Blue Screen of Death [BSOD]

These Windows errors are caused by problems with devices, device drivers, or a corrupted Windows installation. Begin troubleshooting by searching the Microsoft website for the error message and a description of the problem.

BSOD Causes

http://support.microsoft.com/

BSOD Solutions

macOS Pinwheel (continuous spinning cursor)

Black (Blank) Screen

Blank screen when you first power up the computer, and you can hear the fans spinning and see indicator lights:

Misc