Weird PSU w/ that's Always On, Corrupts BIOS

Nov 22, 2017
Hi guys! Here's a weird one for you:

I recently bought a new PC, and decided to use the old one as a media/gaming center in our family room. I used my old PSU for my new build, so I had to find a replacement.

I dug around in the garage and found an old desktop machine with a 600 watt PSU and decided to use that. BUT, here's the strange bit:

The old PSU works fine, but it has no power switch. It turns on as soon as you plug it in. Currently, in order to boot up the machine, I plug the power cable into the PSU, and everything boots. We play games, eat pizza, and generally have a good time.

BUT, I'm unable to turn the machine off in a stable way. If I tell Windows to power down, it attempts to shut down, but the PSU stubbornly continues to provide power. And, for whatever reason, this breaks the BIOS. I have to clear the CMOS in order to get it to boot again.

My current solution for shutdown is simply closing all the programs I can, then ripping the power cable out of the PSU. Which pisses Windows off, but saves me the hassle of clearing the CMOS every time.

Anyone have a good explanation? Or a solution for the problem that DOESN'T involve buying a new PSU? This machine is just for fun, and I don't intend to spend a dime on it. Is there some program that can make Windows 'safe' for a hard shutdown? Or maybe there's a BIOS setting that will allow me to shut down normally?

Thanks guys!
Does the old 600 watt PSU not have a name on it? Just because it does not have a power switch on the back should not matter. Some older PSU's did not have a power switch and they still work the same way a PSU with an on/off switch works. The on/off switch is just meant as an alternative to unplugging the computer. The old 600 watt PSU must be defective.