Problem: Failure to Power Up PC

[evlnchow]

Hello all. My PC just suddenly failed to power up this morning and I have no idea why. I put it to sleep mode last night and when I push the power up button this morning as usual, there was no sign of waking up. The reboot button didn't work either. There was a low humming and I think I felt the fan working within the case, just no sign of power up of the system. Then I turned off the main supply power from behind the case, and the humming slowly died down. Turned the supply back on and thereafter no signal or sound or whatsoever, just dead.

Motherboard: Asus A8N SLI
CPU: Athlon 64 X2 4200+ (Socket 939)
RAM: 2GB DDR
Video card: GTS 250 1GB
Power Supply: 450 Watt

Lately I've been putting it to sleep mode constantly and rarely shut it down. Could this have caused the power failure? Or did the power supply overload or what? The CPU and Video Card were upgraded to the present spec in the summer.

I'm not familiar with hardware failures at all, so any help would be much, much appreciated!

 

[mi1ez]

What make, model and spec of PSU is it?

 

[blacksheep101]

Does your motherboard have one of those green LED lights on it to indicate whether or not it's recieving power?

Open your case, see if the fans in the psu spin when you power on the machine - if not, the PSU's gone

If the fans do spin/LED green light is on, i'd remove the RAM and confirm that your motherboard is still ok (would expect bios beeps with no ram)

If the 450W isn't brand name i'd suggest it's a little too small for a GTS 250. Never skimp on your psu purchase!

 

[evlnchow]

No the fans aren't spinning, so I guess the PSU is gone... but if so, what I don't understand is the first time I pressed the power up button the fans did spin- it's just that the system was not powering up. Then the fan died down when I switched off the power supply from behind the case. If it's a PSU failure then why was the fan still spinning at first?

Sorry if it's a stupid question, but I'm just curious.

The PSU was a brand name but which I forgot, and yes I agree it seems a bit too small for a GTS250 but I was too lazy to upgrade it and just wanted to give it a push. So that's the reason it failed? And there's no way it could be repaired/ used again?

Thanks.

 

[blacksheep101]

May be that the the PSU was on the way out, wasn't able to provide enough current to get the system started and was just generally struggling.

What's more important than total W of a psu is the amount of current it can supply on the 12v rail. Effeciency too. You need to have a bit of headroom in a PSU, i.e. if your system requires 400w you don't want a psu to only be supplying 450W as the effeciency decreases as total load on the PSU increases and this could also lead to its flakyness. I think...

I wouldn't bother repairing a PSU, probably because I don't know how to do it, plus there's a usually monster capacitors inside which I don't really want to touch...

To confirm whether or not the PSU is definately dead you can unplug the main atx connector from the motherboard, bring some pins with a paperclip and simulate the mobo telling the psu to turn on, then you'll be able to tell whether or not its definately dead.