PC turns off before finished booting

DamoKen

Hi, got a weird one here I haven't seen before. Built the PC in Oct '07, only problem to date was a faulty pump last year so removed that and put in the stock CPU cooler and no problem since.

However last night turned it on and it cut out just after post. Thought I must have hit the plug at first as it was a total loss of power. Wasn't the case so tried again.

The mobo is a BFG nForce 680i SLi (Socket 775) PCI-Express DDR2 which has a LED readout that you can read the post codes from. So checked that and it was getting as far as FF which is BOOT.

Monitor was also displaying, got as far as the windows screen informing you that your pc didn't close correctly and giving you the option of starting in Safe Mode. Before I could select it cut again. I retried immediately and it cut before this screen.

Anyone any ideas? Only time I saw this before was when the pump went due to overheating but never this fast. Then I could at least get into the bios and check it's temp etc.

The first start last night was a cold start, hadn't used it in 24 hours so can't see how if it was a heat issue it hit critical temps so quickly.

All fans including the CPU seem to be spinning ok. Couldn't see any wires touching anywhere so don't think it's a short.

Power supply is a Corsair HX 620W ATX Modular SLI Compliant Power Supply so would be surprised if that's on it's last legs!

At a bit of a loss here as haven't moved it recently, upgraded, or anything else that I can think of that would cause this.

Any suggestions for how to diagnose this would be appreciated!

Cheers

uberpixie

1) Get a linux live disk and test with it.
e.g ubuntu live disk from here :http://www.ubuntu.com/getubuntu/download

If you can boot into ubuntu and broswe the web etc it will rule out CPU, GFX card, Ram and motherboard. And you should be able to read data off your harddrives and back up the critical stuff to a usb drive/external harddrive using this disk as well.

2) Go here and download the ultimate boot cd
http://www.ultimatebootcd.com/

You can use the various tools on it to test you ram, hardrives and CPU stress tests.

Try the above and see how you get on. Should at least narrow things down a little.

DamoKen

Hi UberPixie, I'll give that a go this evening if I get a chance. Didn't have time to do much diagnosis last night as was late and I was knackered. Didn't even check if I could get into bios which should be my first port of call as should rule out some hardware issues. If I can I'll change the boot config to cd.

cheers

DamoKen

Ok quick update on that. No joy, can get into BIOS no problem but same thing happens, within 30 seconds of boot up from a cold start just turns off, in less time second time around

Don't have time to pull it apart this weekend so will have to leave it til next week. Windows seems to be ok though, just doesn't have time to boot, bios seems fine but same deal so have to conclude something is happening on a hardware level.

Weird though, all high quality parts just over a year old, haven't messed with anything in a while .

Again any suggestions welcome, can't diagnose anything at this stage as don't have a chance to check temps etc.

Solitaire

Offhand it sounds like there's a critical hardware problem with PSU, CPU mobo or RAM. Sounds like something is overheating, corrupting data or running out of juice after the POST/BIOS. And if that CPU cooler has come a bit too loose then yes, it can easily hit critical temp after the BIOS as loading the OS is the first time after power-on you load the CPU which gets thirsty for juice and starts spewing heat as a result.

One quick n' easy thing to do at least (if you haven't already) - Memorize your OC settings then pull the plug on that sucker - wipe the CMOS and yank out the battery for ~30 seconds then reinsert and see if you have any change with booting. Could be that the BIOS settings are messed up or that something dying has messed them up. Also check your PC Health in the BIOS to see if you're getting anomalous temp readings indicative of a cooler coming loose somewhere very important

After that if no change in symptoms it turns into the old slow grind. I think if you have a second modern PC handy you're going to have to swap-and-test everything critical bit-by-bit first and see what's popped. Otherwise do a minimum boot - PSU, mobo, CPU, one stick of RAM and preferably onboard graphics. Check stability then start to add boot devices (maybe the optical first to see if you can get into MemTest or Ubuntu) until it comes apart. If even the minimum boot is messing you up then try to swap around RAM modules and PSU (if you have a spare) and see if you have a change.