Are these failing power supply symptoms?

[bevills1]

Today the PC failed to boot with no display to see BIOS entry menu or anything else and just a blank screen. System switched off and booted normally following by 2 or 3 normal reboots since with everything else seeming normal except for a low rattling sound like a fan wobbling on power supply possibly. Do these sound like possible power supply symptoms, or do you think it could be other problems?

[Dr_Layne]

If the noise is coming from the power supply, then yes, I would recommend replacement. Power supplies are inexpensive these days, unless it's a prefabbed computer like Dell, Gateway, HP, etc. Some of these you have to use their proprietary power supplies.

[jagabo]

The rattling could also be a case fan (if you have any) or the CPU fan. If it's the CPU fan it should get replaced soon.

[ROF]

Sounds like a failing power supply. A good test for this is to shut your system down. Leave it off for a few minutes to allow everything to cool down. Attempt to power back up. If you experience the issue where you have to boot several times in order for the BIOS to appear you can almost assure yourself it is a power supply. if it does boot up on first attempt, allow it to boot completely and stress your PC a little. Play a game or something that will raise the temp of all components. Afterwards, shut down your system, Wait for all sounds to stop. You know that end whir the computer makes. Allow that to happen completely and then immediately reboot. If you experience the boot up problem at this time. It is not your power supply but is either your motherboard or CPU that is going.

Cold Boot Issues but will eventually boot: 99.9% of the time it's the powersupply
Warm Boot Issues but will eventually boot: 99.9% of the it's the mainboard.

[rallynavvie]

That's actually a really good method of narrowing things down. However I'd double that by "booting" you mean POST and BIOS boot rather than OS boot. I couldn't cold-boot my DH800 rig into Windows even with a brand new PSU, but it would warm-boot just fine. It ended up being bad caps. Bad caps seem to be a steadily rising issue with many different board manufacturers.

If you can bust open your case you may want to inspect the caps and look for any that are bulging before investing in a new power supply. At least this visual inspection is pretty easy to perform. And that rattling could also be coming from any number of fans. Could even be a hard drive starting the tick of death.