Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Computer Died

Status
Not open for further replies.

markk85

Technical User
Nov 22, 2005
40
GB
Please Help!

I was using my computer this morning and suddenly it swtiched itself off. It wasn't like a windows shutdown - more like the power going.

When I tried to switch it back on it nothing happened. I switched the power off at the plug and then back on again. Now when I switch it on one of the fans is really loud, there is no beep and the monitor does not come on.

Anyone got any ideas what the problem is?
I know this is a bit vague but I am now at work and didn't have time to open the computer up to have a look.

Thanks
 
Possibilities include.

PSU has a fault.
CPU had died
Mobo has died (bad capacitor?)

1st remove everything from the mobo except the CPU (RAM, cards, IDE connectors and unplug the power from all drives.
Inspect the mobo for any signs of bulging or leaking capacitors. If none - try a new PSU and if you get beeps add back components 1 at a time (1 stick of RAM and the vid card should enable you to see it is working so far). If that fails try re-moving and re-seating the CPU with a fresh heatpad. But again, add 1 component at a time - so with nothing - power up and you should get beeps. 1 stick of RAM & the beeps should change. Add the vid card and you should be able to get into the BIOS. Then replace stuff as you wish.

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]
 
Sounds like your power supply is going bad. If you have a multimeter you can verify you are getting power out of it. If it was the CPU overheating it would let you restart it after a few minutes, so when you go home you would know more. If it starts up after sitting it is more likely overheating, if it still acts the same most likely the power supply, and hopefully the power supply didn't take the MB with it.

JohnThePhoneGuy

"If I can't fix it, it's not broke!
 
I have just got a new psu and tried that and no joy.

I have tried disconnecting everything from the MB apart from the cpu and the computer did switch on for about 3 seconds before switching itself off with no beeps or display! Then to switch it on again I had to cut the power at the plug, switch back on and try again.

But now when I try and switch it on, the fans just move a little and then nothing happens.

Can anyone help??
 
Actually I have noticed the ram led blinking continuously. Does anyone know what this means?

The motherboard is a gigabyte GA-K8NS Pro
 
Well now you have that spare![smile] As we say in Texas sorry for the bum steer.

JohnThePhoneGuy said:
hopefully the power supply didn't take the MB with it.

This might have happened, or you could have 2 good PSUs and one bad mainboard.

mkellaway said:
I have noticed the ram led blinking continuously

I have not heard of a RAM LED but that does not mean they do not exist. Usually the blinking light on the front of a case represents HDD activity. Since you should not have a HDD hooked up at this point it may be meaningless. Mine (Asus) stays lit if the HDD is not present or unplugged.

If you have done as stduc has stated above, tried to POST the system w/o HDD, opticals etc connected, just the bare MB w/ video & no RAM, (should beep like crazy) we are down to MB or CPU. Can't hurt to re-seat the CPU & try again.

One other thought...remove the MB from the case and set on a towel or other non-conductive surface. Connect nothing but your new PSU. Short across the "PWR ON/OFF" header with a small flat-bladed screwdriver. What happens?

This place is like a hospital. Some patients do not walk out. If it's any consolation there are plenty of cheap Socket 754 MBs available, CPUs too. Since nForce3 does not support Vista (neither do I!) you might look at this as a sign from above that it's time to upgrade.
 
I have tried all of your suggestions and can't figure this out?

It started off that my computer was booting for about 3 seconds and then switching off.

Then when I switched it on the fans would move a little but not boot up. Sometimes the ram led would also come on on the motherboard.

Now when I try and switch it on nothing at all happens!

Can anyone help?
 
If you are 100% sure it is not the power supply, then you have 2 possiblities. If you turn it on now and nothing happens you might get lucky and it be the switch itself, which is unlikely only because it would power on for those few seconds before, or it is your motherboard. Even if you have bad ram it should still beep at you(99.9% of the time) at least.

JohnThePhoneGuy

"If I can't fix it, it's not broke!
 
I think that now you are down to three possibilities.

CPU has failed.
CPU 'thinks' it doesn't have a heatsink.
Bad capacitors or other mobo failure.

Check for bad capacitors - see
If you can see no bad capacitors or any other signs of damage on the mobo then arm yourself with some isopropyl alcohol & a strip of heat pads and remove the heatsink. Clean off all the old gunge and also gently remove the CPU and re-seat it. Apply the heatpad and re-attach the heatsink. I have had this work!

A final and very unlikely possibility is that the CPU fan has failed. If it won't spin &/or the mobo cannot detect it is spinning then it may not permit the computer to boot up and will shut it sown to protect the CPU.

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]
 
In your situation I would suspect and replace the motherboard, regardless of whether I saw blown capacitors. Obviously I'm just some bloke with an opinion, and you shouldn't casually spend money based on it - but that's what I'd do.

Carlsberg don't run I.T departments, but if they did they'd probably be more fun.
 
It sounds suspiciously familiar. I went through that short start up when I built my latest system.

The issue turned out to be multiple:

1) the Power supply was dying, althoug it was new. If you can hook yours up to one that works (cross the cables over from another computer) you can see if it really is the power supply.

2) I am not so sure about this, but I think the PSU may have compromised the mother board in its agony. Tiger took back the first. The second functioned.

3) In connection with all this was what I suspect to have been a short cause by the ATX cover plate, which means that removing the board will help. It was a pretty smooth Antec case. A cheap plate from Central Computing fixed it. (I'd remove the board and try it on a flat surface when I connect it to another computer, or just stand it up on an anti static bag and see if the fans run.

Summary: It may be more than one thing.

Let's hope it's just the PSU and a short rather than the whole thing. Let us know how it comes out.




 
I've been on holiday for a week so haven't been able to sort anything out.

So the stage I am at now:

When I try to power on the system nothing at all happens.

I know it is not the psu as I have bought a brand new one.

I have checked the motherboard for bad capacitors or any signs of burnt circuits and there are none.

The only thing that I have just noticed upon closer inspection is a small mark on the top of the cpu ajoining what looks to be a printed ciruit. There is also a small raised lump on the bottom of the heatsink in what appears to be the same position. Could this be anything to do with the problem?

What needs to be connected to the computer for it to power up rather than just do nothing?

1) Just motherboard and psu - should it power up or do nothing?
2) MB and CPU - nothing or power up?
3) MB, CPU and Memory - nothing or power up?
4) MB, CPU, Memory and Graphics - nothing or power up?

Thanks for any help
 
PSU+Mobo+CPU(assembled correctly with heatsink) should power up and beep like crazy. At that point you can start adding RAM, then video etc etc.

You may need to re-set the PSU by pressing the power button for 30 seconds or so with no mains power.

If no joy with just PSU, mobo & CPU - and a new PSU it kind of has to be the mobo or the CPU is "dead". To be honest - at current prices I would be tempted to simply replace both.

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]
 
So if I just had a motherboard and psu connected (no cpu) - the computer should not power on?

Is that correct?
 
Try this, reset your CMOS, perhaps something gone bad with it, if not, maybe your BIOS is gone bad, no BIOS no PC at all...

 
So if I just had a motherboard and psu connected (no cpu) - the computer should not power on?

The mobo on it's own - may- or may not power up - but without a CPU how can you tell?

You could verify your PSU with a PSU tester. However if the CPU+mobo won't power up & beep & the CPU fan keep running then I can only repeat that personally I would save time & get a new CPU & mobo.

The only way to tell whether it's the mobo or the CPU is to possess a mobo tester - or a second, known good CPU!

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]
 
I have reset the cmos and the psu - still no joy.

I have also cleaned the cpu and heatsink and put on new thermal compound.

I doubt that it is the bios as the mb has a dual bios and it was powering on for a few seconds previously.

Could it be a dead mb battery? - would this cause it not to power up?

I have taken a pic of the mark on the cpu I mentioned earlier. Could this be the cause of my problems?

cpuwf2.jpg
 
Ok so i've just tried a new motherboard battery and it's not that causing the problem.

Can anyone help?

Does it look like the cpu based on the above pic??

Thanks
 
Does it look like the cpu based on the above pic??

Hard to tell. Looks like the ink on the logo is just smudged to me. If that is a burn mark then chances are the CPU & the mobo could be dead.

You don't need a cmos battery to boot. It just keeps the cmos info - so without one you have to set up from scratch each boot.

I can only repeat - IMHO - you are on a hiding to nothing now. If you try a new mobo that could be wrecked by your CPU - and visa versa - so get both. Just so long as you are sure the PSU is OK. A PSU tester only costs a few dollars - so may be worth the investment.

I guess as one last thro - re-assemble out of the case on a non-conducting surface. With PSU powered up & plugged into mobo & CPU assembled with its fan and that fan plugged into the mobo just use a screwdriver to momentarily short the pins on the mobo that the front switch connects to. If the CPU fan runs then & the mobo beeps you have a case short issue to find & solve.

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top