PC won't start. Any ideas to get it working?

Harrison

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How annoying is this. I was about to order the parts for the new PC I'm about to build, switched on my existing main PC and it booted up fine. Was using it for about 30 minutes and suddenly it switched itself off without warning. I tried to switch it back on but got no response from the front power switch.

So I switched the PSU off, disconnected it from the mains, waited a couple of minutes, plugged it back in and switched the PSU back on. As soon as I switched the PSU back on the system fans span for a couple of seconds, and then the system switched off again. And the front case PSU didn't do anything when tried.

I therefore instantly suspected the PSU had died. So I opened the case up and smelt the PSU and it does have a slight electrical burning smell. And not taking any risked I decided it was better to just swap the PSUs. I have a spare 500W PSU, so I dismantled the system and swapped the PSUs over, but the same thing still happens. When the switch on the PSU is switched on the fans all spin for a couple of seconds then it all switches off again.

Next I stripped the system down and currently only have connected:

PSU
Motherboard
CPU
CPU fan
1 case fan
1 stick ram
Graphics card
motherboard power switch and reset switchs connected to motherboard.

So quite a minimal setup. However it is still doing the same thing. Switching the actual PSU switch on, the fans for CPU, case and graphics card all spin for about 2 seconds then it switches itself off again.

Any ideas what the main cause of this is?

I know the second PSU is OK because I tested it in another system. However I can't test the graphics card or CPU because I don't have another Athlon 64 motherboard or PCI-E based system at the moment to put either into. I am going to try some ram from a different PC in the system next though to see if that is the cause. Otherwise it must be either the graphics card, CPU or motherboard, which is really annoying as I wanted to use this as a second PC for video encoding once I'd built the new one.

However, my main question is, what causes the fans to spin when the PSU power switch is turned on? Normally when the PSU switch is switched on nothing happens other than the motherboard green light coming on. And only when the soft power on switch on the case is pressed do the fans spin and the system boot. So why are they spinning when the PSU itself is switched on? Does this indicate the motherboard is faulty?

And the other irony is that the motherboard and CPU both had 3 year warranties on them, which I think ran out in January!!! Ahhh!!!

Normally I can sort faulty PCs out easily, but without a spare PCI-E graphics card or a way to test the CPU in another system I'm a bit limited and think I've got as far as I can with what I had to hand. Annoyingly this system has never had a single problem until this. It has always booted and never actually had a full system crashed once in the three years of using it. It has been extremely stable.

So am I right in thinking it has to either be the Motherboard, CPU or graphics card? Or can I rule out the graphics card because the system doesn't even power on? I've always thought the system would report a series of error beeps if the graphics card or CPU was bad?
 

Justin

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Re: PC won't start. Any ideas to get it working?

yo dude!!

sounds to me like either bios bettery, or motherboard, do you have any other memory you could test?

JuvUK
 

Merlin

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Re: PC won't start. Any ideas to get it working?

Just a thought; if the default in the bios is set to AGP as the primary graphics adapter, it may shut down as the bios can't see one; as JuvUK says, the bios could have reset itself. Do you have an old PCI (not PCI-E) graphics card you can throw into it to see if a display comes up? I keep an old TNT2 PCI video card in the toolbox just for situations like this.

The lack of beeps or alarms hints that the system is getting past the POST, so it is likely to be a CPU or display issue. If the PSU died horribly there could have been a spike sent through the board causing damage that you can't see.
 

Harrison

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Re: PC won't start. Any ideas to get it working?

Sadly I don't have any old PCI graphics cards still around to try. All my older systems are AGP and I've not used a PCI graphics card for over 10 years. This system is the first I've owned with PCI-E, which is a bit annoying as until now I've just been able to try one of my many old spare AGP cards in a faulty system.

What happens if no graphics card is installed? Shouldn't the motherboard give out a beep error because it can't be found? I'm sure some of my other systems did this in the past.

I've tested the ram in another system and it works fine, so it isn't the ram.

I reset the BIOS by clearing it using the motherboard jumper, but that didn't help.

I do have some spare batteries so will try swapping that over next just in case it is something that simple.

The thing I don't get though is that the fans are spinning up for 2 seconds when the PSU's own power switch is switched on, not when the system power switch is pressed. So I'm not even getting to the point of trying to switch the system on. I connect the power cord to the PSU, switch the PSU on, the fans spin for a couple of seconds then switch off, the green light is on on the motherboard, but after this the system is dead. Pressing the case power switch doesn't do anything. The fans don't spin and nothing happens.
 

imnogeek

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Re: PC won't start. Any ideas to get it working?

It is quite normal to get a quick burst of fans when the power supply is plugged in - the MB is live all the time on an ATX PSU.

I would have thought it unlikely for the bios battery to be at fault as it shut down during use.
Unless you have had a major failure of MB/CPU etc then I would suspect a short so try these...

Did you unplug Keyboard an mouse when trying it? if not unplug them and try again.
Take MB out of case and lay on non conductive surface ( I normally have it standing on some plastics board mounts to raise it off the surface)
leaving in RAM (which you could swap to another slot if you want to rule the slot out), gfx card, cpu and fan and MB power connector and plug in monitor.
do not plug in keyboard, mouse, any ide/floppy cables etc
now turn on by BRIEFLY shorting the 2 power jumpers with the tip of a screwdriver

if no luck unplug monitor too you will see if the fans spin constantly then.

this should rule out any shorts from the board touching the case or a loose screw in the case etc.
 

Justin

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Re: PC won't start. Any ideas to get it working?

@ Harrison,
i can send you an old pci card i have kicking around here if you like?

cheers, JuvUK
 

Kin Hell

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Re: PC won't start. Any ideas to get it working?

@ Harrison

When you flip the Battery out, Pull the CPU & the Ram, put CMOS reset jumper in place & go make a coffee. Drink coffee, Put CMOS jumper to run, re-fit CPU & ram, then try again.

Bios corruption can be a b!tch.

Other than that, the Mobo Power Regs could be FuX0rd. Have you checked for Blown CAPS?

Good luck!


@ imnogeek

imnogeek said:
It is quite normal to get a quick burst of fans when the power supply is plugged in - the MB is live all the time on an ATX PSU.

Only if you use cheap nasty un-switched PSU's. Get yourself a Good Branded PSU & you don't get the Fan Twitch/Surge when plugging in! :wink:
 

imnogeek

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Re: PC won't start. Any ideas to get it working?

Only if you use cheap nasty un-switched PSU's. Get yourself a Good Branded PSU & you don't get the Fan Twitch/Surge when plugging a Live PSU into your Mobo!

which applies for most Dells ;)

edit: sorry forgot to say I don't know what he has in there so it could still apply.
 

Harrison

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Re: PC won't start. Any ideas to get it working?

The PSU is a Thermaltake TR2 500W so it should be OK.

One of the first things I tried was to strip the whole system down. I removed the motherboard from the case (as I wanted to use this case for the new system anyway so it was being moved at some point), set the motherboard up on a wooden surface. Had just the CPU, RAM, Graphics card and PSU connected up. Nothing else. Tried to power it up and the same thing happened. The fans spin for two seconds when the PSU power is switched on, then nothing. And shorting the power on doesn't do anything.

I've tested the RAM in another system and that works fine so that can be ruled out.

I'm removed, cleaned, applied new thermal paste and remounted the CPU and heatsink. No difference. And while the CPU does have a head spreader covering it, normally you can see some sign of damage if it has shorted, and it looked fine.

So I think it has to be either the graphics card or the motherboard itself.

I keep mentioning the fans spinning for two seconds when the PSU power switch is first switched on because this never happened before. The fans wouldn't not move until the front case power switch was used. So it is behaving differently making me think it is the motherboard. But I would like to rule out the graphics card first.
 

Harrison

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Re: PC won't start. Any ideas to get it working?

Kin Hell said:
@ Harrison

When you flip the Battery out, Pull the CPU & the Ram, put CMOS reset jumper in place & go make a coffee. Drink coffee, Put CMOS jumper to run, re-fit CPU & ram, then try again.

Bios corruption can be a b!tch.

Other than that, the Mobo Power Regs could be FuX0rd. Have you checked for Blown CAPS?

Good luck!

I've checked the board all over closely when I removed it from the case and it all looks in good condition. No buldging caps or funny coloured stuff oozing out, so that didn't reveal anything.

I've also had a good look at the graphics card and that looks fine, although that isn't always the case.

I didn't pull the ram and CPU when I tried clearing the CMOS. I will try that now and see what happens.
 

Harrison

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Re: PC won't start. Any ideas to get it working?

JuvUK said:
@ Harrison,
i can send you an old pci card i have kicking around here if you like?

cheers, JuvUK

That would be very useful if you could.
 

Justin

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Re: PC won't start. Any ideas to get it working?

no worries m8y, pm me your deets and i'll get it on it's way :D
 

Merlin

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Kin Hell

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Re: PC won't start. Any ideas to get it working?

@ Merlin

He couldn't be unlucky enough to have 2 x grey atx wire faults could he?

He already swapped PSU's out m8! :wink:

Kin
 

Harrison

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Re: PC won't start. Any ideas to get it working?

The PSU is working fine. I don't have a multimeter here (lost it somewhere) so I can't test the lines. However I tested the PSU to see if it would stay powered on by shorting the green power-on wire across to a black ground and the PSU powered up and stays on.

And I also connected it to an older spare PC and that booted and worked perfectly. So it definitely isn't the replacement PSU I'm using.

BTW, I finally had to remove the old PSU from the house. I didn't think is spelt much at all, but I went downstairs to get a coffee and came back up and the smell was quite strong in the room. So that definitely died!

So I think I have narrowed it down to graphics card or motherboard.

This is so annoying. I had some freelance design work that needed to be done today too, and while I do have a few other PCs, the work was all on the main system and none of the software is installed on any of the others. I might take a trip to Novatech in Portsmouth tomorrow morning and pick up the parts for my new PC and spend the day building that so I can get back up and running to get the freelance work done.

I was just thinking. We had a powercut on Sunday here. The PC wasn't switched on, but the power cable was still connected. Could the power cut have caused the PSU to die? The PC was working yesterday, but then died when I switched it on this morning. So I'm wondering if that somehow weakened it enough for it to overload? If so it was plugged into a Belkin surge protector with a lifetime warranty. Anyone know if that could be claimed against? Or failing that what about the house insurance? As I'm building a new system I can leave the dead one semi built for any insurance claim assessors to look at. What do you think? Good idea? Or a waste of time trying?
 

Harrison

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Re: PC won't start. Any ideas to get it working?

Justin is posting me an old PCI graphics card tomorrow so that will see if it is the graphics card or not, and then it would all indicate the motherboard is fried.

Can anyone suggest any online stores that still have any 939 motherboards in stock? Novatach has one low end Asus board which would probably be OK, but it is over £60 and not that great a spec. Microdirect, ebuyer, Dabs and saverstore don't have any at all any more. Anywhere that might?
 

imnogeek

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Re: PC won't start. Any ideas to get it working?

The power cut may have had a bearing on and the old PSU failing but I think the surge protection should definately have taken that not your PC.

I think it would be reasonable to assume the motherboard is damaged as a result of the PSU failing - which they often do when they are turned on after being off for a time (I hate powering down a server for exactly that reason)

I would invest in a small UPS suitable for your new PC you should get a reasonable one with monitoring for about £40-50.
 

Justin

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Re: PC won't start. Any ideas to get it working?

there are a load of them on the other "bay" under 939 motherboard if thats any use to you m8

JuvUK
 

imnogeek

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Re: PC won't start. Any ideas to get it working?

overclock.co.uk have 2 ASRock 939NPV-GLAN in stock
 

Kin Hell

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Re: PC won't start. Any ideas to get it working?

Alot of 939 boards have Bios Issues when the batteries run low, particulary nVidia Chipsets.

If it's a dual channel DDR Ram board, make sure the ram is in the right slots. DFI 939 boards are a nightmare on Dual Channel Ram & DIMM 0 & 2 isn't always the right thing to do. I just serviced a DFI LP nF4 SLI DR Expert board that wont work properly, unless the Ram is in DIMM 1 & 3. Also, 1T Ram Timings are more stable on 939 than 2T Timings. You will need to know exactly what ram is fitted as it might not be suitable for this Mobo/CPU combination.

Kin
 
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