Caps are short for capacitors.

When it freezes again, try unplugging it and hitting the power button. Then plug it in for a few seconds, remove the power and hit the power button again.

This should charge all the caps on your mobo and in your psu and then empty them. If this 'fixes' the issue and lets you boot you probably have some bulging or blow capacitors on your mobo or in your psu.

Inspect the inside for cylinders sticking out perpendicular to the surface of the PCB. The should have small lines across them that are perforations. If they have any residue on any of them this may be your issue.