PC partially powers up when ac cord plugged in

[StinkyPinky]

I have a weird problem on a new pc. When I plug in the mains power to the psu, the pc partially powers up. By that I mean the system fans all start and the dvd/hard drive have power. However it doesn't post or boot up until i press the actual power button

The reverse is true when I go to shut down (either via the shut down command or just by pressing the power button). The system only partially shuts down - the fans and drives still run. The lights are on but nobodies home so to speak.

I've tried unplugging all my drives and fans, and just having the psu connected to the mobo and it still does it.

I've tried updating my bios but the problems remains.

Could it be a faulty psu?

 

[mpilchfamily]

What PSU is it?

If i had to point fingers i would say its the motherboard. When you press the power button on the case 2 things happen. It tells the motehrbaord to complete the cuircute to turn on the PSU and it starts the motherboard on the boot prosses. When you shut down the system windows does everything it needs to sut down properly then hands control too the Motherboard so it can break the curicut and turn off teh PSU. It sounds like that curicut is remaining closed allowing the PSU to remain on all the time. Then once the power button is pressed the system starts its boot prosses.

If you can get ahold of anotehr PSu and try it then do so. It will be good to definativly rule out a PSU problem. But i'm pretty sure you'll get the same result even with a new PSU. So what i recomend is backing up everything on the HDD. Cause if you don't replace the motehrboard with the same model board you'll be forced to reistall windows and you don't want to loose your data.

 

[StinkyPinky]

It's just a cheap antec psu that came with the case for a budget system. I've done some further testing and actually think it's the psu. I've totally isolated it from the pc, and just plugged it into the mains and it runs by itself. I've even tried a different cable and power socket. I'd rather it be the psu than the mobo so here's hoping it is

 

[StinkyPinky]

Now they want me to send the entire case back, rather than just the psu. Grumble grumble. Pain in the ass. Now I need to take everything out.....grumble grumble.

 

[bendixG15]

Check the main onn/off switch in the front, probably sticking.

 

[Schmide]

I had an antec PSU do the exact same thing. Just saying...

 

[StinkyPinky]

Originally posted by: Schmide
I had an antec PSU do the exact same thing. Just saying...

What did you do?

 

[Schmide]

Got a new PSU. Well I had an one on hand. Ultra XConnect FAR FTW

Edit: BTW it was an Antec 350 Watt Model: SL350 Smart Power 2004