PC switching itself off and failing to power properly

ixoy

My PC abruptly switched itself off last night. I left it at that and decided to worry about it tonight.

Today, after checking it for dust, I turned it on. It booted for a few seconds, then powered down immediately. Did it again - same thing. The motherboard light showed was green, indicating that it was at least connected to a power source.

Now I left it for a while and, so far, it's not switched itself off. Given I was booting up from cold, it couldn't be a CPU overheat as happened to me previously. I also had disconnected my 2 other HDs before trying to power it up the second time but it still died on me...

Any thoughts? Since it didn't power, there was no beepings for me to investigate...

aidan_walsh

Would you be able to swap in a second PSU and check see will it boot with that?

ixoy

aidan_walsh wrote:

Would you be able to swap in a second PSU and check see will it boot with that?

Well I don't have a spare one as I blew the one on my last one. It's been working fine now for a number of hours but PSU would seem to be the most obvious problem. Trouble is, how do you test when it works now and then?

Endurance Man

I would say this was a psu problem. My pc used to do the same thing, got a new psu and all was well. It usually happened to me after a few hours of CSS, or any other heavy game, what are u doing before it switches off ??

ixoy

Endurance Man wrote:

I would say this was a psu problem. My pc used to do the same thing, got a new psu and all was well. It usually happened to me after a few hours of CSS, or any other heavy game, what are u doing before it switches off ??

Yesterday I was watching a .avi file which I can't imagine consuming too much power as it's something I do fairly frequently. Not sure how it'd explain it switching itself off on bootup today unless it's just a general symptom of a dying PSU. As it is, it is generally a bit overloaded - 350W with a Geforece Ti4200 GFX card, 3 HDs, 1 DVD drive, 1 DVD-RW, and 1 floppy eating off it. Yes I know...

vibe666

this is your most likely culprit at the moment:

http://securityresponse.symantec.com/avcenter/venc/data/w32.zotob.e.html

It has been reported that computers targeted by W32.Zotob.E may become unstable during execution of the exploit code. This may result in the termination of the services.exe process, which causes the targeted computer to shutdown.

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Nocturnal

Yeah the same thing happened my power supply,was just watchin an avi and the commputer powered off,tryed powering it up and just one of the lights on the mobo came on,i reckon that the power supply blew and that was running off the battery on the mobo.I then did the test,get a wire and connect the green wire to tthe black wire and powring on,didnt work,told komplett and rma'd it on monday,its ur power supply

Nocturnal

vibe666 wrote:

this is your most likely culprit at the moment:

http://securityresponse.symantec.com/avcenter/venc/data/w32.zotob.e.html


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I dont think this would stop you from powering your computer up again either,it just ends a process,doesnt blow your psu!

vibe666

Nocturnal wrote:

I dont think this would stop you from powering your computer up again either,it just ends a process,doesnt blow your psu!

there i go again, not reading posts properly. :rolleyes: didn't notice that it wasn't powering up past post when i first read it. D'oh!

I had something a while ago when I got a new PSU, but it was happening on my old PSU too.

I thought it was insufficient power, but it stopped happening after a while, and when I put my newer PSU in it never happened again on that either.

my thoughts at the time were maybe poor earthing or something like that, but I never did figure it out.
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spooydermot

had you been experiencing any sudden reboots over the past couple of weeks? They are usually the first sign of a failing PSU before it starts shutting down the computer.

ixoy

spooydermot wrote:

had you been experiencing any sudden reboots over the past couple of weeks? They are usually the first sign of a failing PSU before it starts shutting down the computer.

*bump* Yeah I had a couple of times... Defintely sounds like a PSU problem although it's not died since I disconnected the 2 extra HDs. But that's only stalling the inevitable.

Has anyone recommendations for a new, better PSU? It needs to power:

* GeForece 4 Ti4200
* 3 HDs (120/160/160) GB
* 1 DVD/R-W
* 1 DVD/CD-ROM
* 1 Floppy Disk
* An Athlon AMD 2500XP+
* An Asus 798X Deluxe V2.0 Motherboard

The old PSU is 350W - clearly not enough. It came with my case, which is a compact one Antec Lansang model. I assume that PSUs are generic and I should be able to take out theirs and replace it with my own with only a small bit of hassle? And are PSUs specific to chips/boards? Cheers!

Nukem

Fill your exacts in here - you could just unplug the two DVD drives and see if it runs smoother then ya defo know its the PSU. Just check your mobo probably has a 20pin main connector. There are a few nice 2nd hand ones around the F/S forum. Dils 450w Coolermaster would be nice.
Also that virus you speak of vibe - had it in work and it auto shuts down on start up with a gammy counter clocking down. very annoying.

Nukem

ixoy

Nukem wrote:

Fill your exacts in here - you could just unplug the two DVD drives and see if it runs smoother then ya defo know its the PSU. Just check your mobo probably has a 20pin main connector. There are a few nice 2nd hand ones around the F/S forum. Dils 450w Coolermaster would be nice.

Cheers - it calculates a 305W power requirement. I've a 350W supply, so it should have been able to cope....

I've currently the 2HDs disconnected. It hasn't died on me as such lately but I still fear it will..

I take it though that 20pin is the standard PSU? I'll find those pins somewhere I'm sure (amazed at how clueless I am about PC hardware..). But, in general, PSUs are interchangable right?

[Edit] My PC is, apparently, an ATX12V with a 20-pin main power connector, a 6-pin AUX power connector, and a 4-pin +12V motherboard connector. Sounds about standard I think [/Edit]

Endurance Man

Fill your exacts in here - you could just unplug the two DVD drives and see if it runs smoother then ya defo know its the PSU. Just check your mobo probably has a 20pin main connector. There are a few nice 2nd hand ones around the F/S forum. Dils 450w Coolermaster would be nice.
Also that virus you speak of vibe - had it in work and it auto shuts down on start up with a gammy counter clocking down. very annoying.

Nukem

Wow, thanks for that link, what a great resource. Filled in all my ****e and im rated at 349w, and i have a 350w . Dont think im gonna push my luck any more. Got the new psu, just need to sleeve it and im away . Ixoy, if your just on the limit i would get a new psu, but u seem okay with 305w.

jor el

ixoy wrote:

Cheers - it calculates a 305W power requirement. I've a 350W supply, so it should have been able to cope....

I've currently the 2HDs disconnected. It hasn't died on me as such lately but I still fear it will..

I take it though that 20pin is the standard PSU? I'll find those pins somewhere I'm sure (amazed at how clueless I am about PC hardware..). But, in general, PSUs are interchangable right?

Just make sure whatever PS you buy isn't a Q-Tech, they're crap. Also, just because the supply says it's 350W doesn't mean it can actually supply that much power. The Q-Techs for example don't supply the power that it is rated for, so perhaps yours is similar.

Anyway, most new supplies will have 24/20 pin connector off it so you can use it on any motherboard. I have a Jeantech supply from PC World like that. Changing the power supply is easy too, just unscrew the old one and replace.

ixoy

jor el wrote:

Just make sure whatever PS you buy isn't a Q-Tech, they're crap. Also, just because the supply says it's 350W doesn't mean it can actually supply that much power. The Q-Techs for example don't supply the power that it is rated for, so perhaps yours is similar.

Yeah I hovered over a Q-Tech in Maplin but I seemed to recall it being slammed here on Boards. I'll order another one in a few days time, or after my holidays. It actualyl seems straight forward enough, having a look down at it so I should be able to manage it and not blow my PC up (as I've done with an old machine...).