pc random switch off annoyance

[admars]

Hi
I've mentioned this before in another thread but my PC just switched itself off twice

the other day I turned on PC when I got in from work and it switched itself off just before boot menu.
I think a day or so later it switched itself off when it was loading openSUSE, i.e. after bootmenu

today it switched itself in the middle of writing a post. Then when i turned it on again it switched itself off after bios check etc as it was starting to draw the boot menu.

so I took side case off to see if much crud inside, and not much.

I unplugged and plugged back in graphics card, memory, and hard drives.

a week or so ago I did hard disk scans using proprietary boot cds for each hard disc (one samsung one Seagate) showed no problems and I ran memtest86+ no problems

if/when it happens again, what would be next thing to try?

I haven't got a spare suitable PSU.(650watt ezcool)
graphics card 8800gts 512mb ( i still have the old 7300GS)
mobo is asus a8n-vm
processsor AMD x2 3800

it's weird though that it hasn't happened while in XP playing Bioshock, Spore, Crysis, or Sims 2.

Missus said she was on PC most of today playing games so it seems unlikey to be an overheat or PSU issue.

Any ideas?

Cheers

Al

[Mick Fisher]

When you say 'switched off' do you mean a spontaneous shutdown?

If so then I had this problem back in the w98x days. It started out as an occasional occurrance but got worse over time until the machine was spontaneously restarting as well. Completely unusable.

It turned out to be a faulty power button.

[admars]

sorry yes, I did mean "spontaneous shutdown"

faulty power button, hadn't thought od that, woudl that involve getting a brand new case then, or is is liekly could just replace the swicth/a spring?

Cheers

Alan

dodgy power supply or failing motherboard. Other poss is temps is your cpu fan spinning? could be a short on the mobo any screws come loose? or a dry joint on the PCB. Simple way ot testing the switch woudl be to remove the power on cable from the mobo and start it up by shorting the pins. If it shuts down again you know its not the switch

[admars]

Originally Posted by David F

dodgy power supply or failing motherboard. Other poss is temps is your cpu fan spinning? could be a short on the mobo any screws come loose? or a dry joint on the PCB. Simple way ot testing the switch woudl be to remove the power on cable from the mobo and start it up by shorting the pins. If it shuts down again you know its not the switch

err that doesn't sound very safe! i wouldn't know how to do that either, and I'd be worried about making it worse.

Fans seem to be spinning fine. As i say it'll will hapily be playing some games all day fine for days on end, then another day i go to turn it on and it shortly turns off. I've never had it not turn on when I've pushed in the power button.

David - I know you're a fan of certain makes of PSU, and regularly warn ppl off cheap ones.

In your experience are EZCool one to avoid? I bought it on a friend's recommendation. he builds various machines and found them to be good value for money, i.e. reliable but not too expensive.

What were the couple you regularly recommend please in case I do go down that route. What watt PSU would you recommend for my machine? . in addition to the spec mentioned above there are 2 hard drives, 1 DVD ROM, 1 DVD+-RW.

Cheers

Al

OCZ Seasonic Antec are 3 there are more good ones 600/650 will be plenty. However we do not know what the cause is yet so do not spend any cash. As for shorting the pins ive done it loads of times never done damage yet touch wood however if you are not comfortable fair enough

[admars]

I wasn't about to rush out and buy one, just thought I'd kep my eye on Aria etc on their "Deal of the Day" type "bargains".

I could give the shorting the pins a go, the only problem with that is I'll have to do it like that every day, and it could be fine for a while.

Cheers for the advice.

just sit on it for a bit then dude

[dragon]

Originally Posted by admars

err that doesn't sound very safe! i wouldn't know how to do that either, and I'd be worried about making it worse.
Al

That's all the Switch does is complete a circuit between the pins it plugs onto it.

Indeed its perfectly easy to start a pc by shorting the pins just make sure you short the PwrSw pins and nothing else.

[admars]

I knew I had posted about this before. Same issue started happening this morning, has been fine for years!

has switched itself off a few times (as in if I pulled out power lead) at various stages from being in OS, to boot.

So I thought I'd try a live cd, as soon as I hit eject button after powering on, switched itself off.

so I pulled out geforce 880gts 512, plugged monitor into onboard, PC started into livecd, started to run memcheck for a bit was ok, rebooted, it went into an OS fine, used for a bit, rebooted again ok.

I switched it off, put 8800 back in, again, it switched off shortly after boot.

so I put 7300gs in, again it switched off shortly after boot, before HD checks, CD checks etc.

PC is again up and running now using the onboard graphics.

So, that looks like PSU could be problem. I've got the old PSU that came with PC, but I think that's only 250watt, but was ok with 7300 a few years ago.

I can probably try 8800gts in Father in law's PC later today.

Any other suggestions?

thanks

Al

---------- Post added at 10:58 ---------- Previous post was at 10:13 ----------

crap, been using if for a while, and it switched itself off, so back to beginning of this post for suggestions about shorts etc

guess I'll try old PSu with 7300

---------- Post added at 12:14 ---------- Previous post was at 10:58 ----------

so far so good with the 250Watt HCI PSU and 7300GS graphics card

[admars]

Cheers, pc has been running problem free since my post earlier at lunch time using the 7300 and the old 250 watt PSU, so looks like if the PSU is faulty it hasn't done any damage to other components, unless it already has to graphics card.

[Gavin78]

Was going to say take the CPU fan off and give it a good clean I had a problem with that once and put some clean compund on.

But looking further into your post it does seem like a PSU problem, I can't speak for other sites and shops but Ebuyer do some pretty good and not too expensive PSU's

[admars]

cheers, been happily running for 10 hours now, I'm tempted tomorrow morning to go back to the EZCool PSU and see what happens.

I may order
Corsair 600W CX PSU - 2x PCI-E 6x SATA
http://www.ebuyer.com/product/241000
or
OCZ Stealth Xstream II 600W PSU - 3x SATA 2x PCI-E
http://www.ebuyer.com/product/204353

I think either of those should fit the bill

both are around £55 most places I've looked

Cheers
Al

[Lister of Smeg]

Originally Posted by admars

cheers, been happily running for 10 hours now, I'm tempted tomorrow morning to go back to the EZCool PSU and see what happens.

I may order
Corsair 600W CX PSU - 2x PCI-E 6x SATA
http://www.ebuyer.com/product/241000
or
OCZ Stealth Xstream II 600W PSU - 3x SATA 2x PCI-E
http://www.ebuyer.com/product/204353

I think either of those should fit the bill

both are around £55 most places I've looked

Cheers
Al

Bot PSU's as above are fantastic. The OCZ warranty is a straight swap so if you've got issues in the future, a chap will come to your door (within 3 yrs) and give you a replacement and you'll hand over the faulty one.

A plus for Corsair PSU's they tend to have a 5 yrs warranty (no swap out I'm afraid) but the fans used are genuinely very quiet. But either way, they're just as good as each other.

If cables are an issues, you may want to consider a modular PSU?

550W OCZ Fatal1ty Modular Power Supply £55.80

600W OCZ ModXStream Pro Modular Power Supply £63.36

[admars]

Cheers, I ordered the corsair from http://www.cclonline.com earlier today, 54.99 inc next day delivery. I don't really need modular one, and wanted to get the cheapest good one if you see what I mean.