POST (Power-On Self Test)

Category: science

A series of system checks performed by the BIOS when a computer is first powered on.

The POST is the "first-breath" check. It verifies that the CPU, RAM, and essential hardware are functional before handing control to the OS. A "POST failure" is the most common reason for a new PC build to power on but show a blank screen.

Common Examples

• If your computer powers on but shows no signal, it is likely failing the POST due to an improperly seated RAM module.
• Clear the CMOS settings to reset the BIOS if your system is caught in a persistent POST loop.