Help with booting issue

[bulldogs6]

My computer will only boot if the power cord has been unplugged for at least 20 minutes before. So now every time I shutdown my comp I have to pull the power cord out so I can boot it up next time I need it. If I try to turn on my pc when the cord has been left in before it does nothing, does not power up at all.

Does anyone have any idea as to what is wrong with my pc?

Also I noticed that when the power cord is plugged in and the pc is not on, I can hear a faint humming, when I pull the power cord out I hear a bleep and the humming goes away.

I’ve tried a couple of different power cords so we can eliminate that, do I need a new psu or could it be something else?

 

[goombawaho]

It could be the motherboard or a power switch, but I'd bet on the power supply going bad. Can you borrow one from a friend or better yet borrow a power supply tester (although I've seen where it says the power supply is okay, but then I put in a new one just to test and the PC starts right up).

Best bet is to plug in a test power supply.

 

[wahnula]

Clear CMOS (short across the Clear CMOS headers, or remove the battery and press and hold the power switch for about 15-30 seconds.

I will also bet it's a bad PSU. If you don't have a spare PSU, that means you need one!

Tony

Users helping Users...

 

[goombawaho]

I think Wahnula means disconnect the AC from the power supply and then try what he said. That procedure is usually applied to laptops (since they have their own battery), but can't hurt to try with a desktop.

 

[Grenage]

Bound to be the power supply, the fault you describe is pretty common with failing units.

"We can categorically state that we have not released man-eating badgers into the area" - Major Mike Shearer

 

[goombawaho]

Yes ^^^^^ that would be my free, not-on-site diagnosis if I had to give one.