Power on for 1 second then instant off.

[cgbeige]

It might be that the OS starts a task that drives the PSU over a certain power draw, where it fails.

You can try memtest to see if it's the RAM

[DanielWray]

It doesn't even get to POST.

I'm fairly certain it's either the PSU, the motherboard or CPU as even with RAM trouble it tends to boot to POST and then fails.

I'm just wondering if there are any tell tale signs of it being one component as I don't want to go out and purchase a PSU, motherboard and CPU if it's just one component and I know how finicky places can be with returns so I'm a little cautious.

[olson]

I would start with the power supply. If you have another machine then you can swap them to test. Also check that the heatsink for the processor is secured as a loose heatsink could cause the same instant shutdown problem.

[DanielWray]

Hey,

I was looking around the house for a spare supply but I don't have one.

I did remove the CPU power cable + fan cable and the PSU then stays on, plus all of the fans and LED's etcetera so I'm going to take a guess and say the CPU has either fried or something on the motherboard related to the CPU has gone.

I also noticed the CPU was a bit slack, which is weird as it's been working fine for the last 2 or 3 years and I've been moving it about a lot, and occasionally knocking it while it was running so if that is the cause then I'm surprised it's lasted this long.

I think a new Motherboard and CPU are on the cards though as I'm fairly certain the PSU is fine.

Sadly I'll have to go for an AM2+ motherboard as I have 6GB of DDR2 that I don't want to throw away, and purchasing a Q6600+ would cost twice as much as a an AMD X4 2.5GHZ and motherboard!!!

[olson]

Don't order that new stuff until you find out the condition of the power supply. If you have an old motherboard you could plug it into the power supply to test, or get one of those $15 power supply testers at a place like Fry's. Good luck with whatever route to take and be sure to ask questions here if you've got them.

EDIT: Right, no Fry's there. Whatever electronics store you have there will probably have an ATX power supply tester.

[DanielWray]

Bit of an unscientific test; I tried my PSU with another motherboard and CPU, however I had no heat-sink so I just strapped the fan onto the CPU and tried powering it up (I have nothing to lose, it's old gear) and the board started up, the CPU was giving off heat so I know my PSU can power it.

However I've noticed my PSU has a main-board power connector plus a connector which goes a long side this with the letters '24' written on it, I noticed it's the same type of connector as the CPU1 & CPU2 connectors from my PSU and I'm wondering if it's part of the CPU power supply?

If it isn't then I think I could potentially cross the PSU off the list as it's powered another board + CPU and that is the only time the machine turns instantly off is when CPU 1 or CPU 2 connectors are attached to the motherboard.

I'll try and pick up a meter just in case to test out the PSU but since it's a fairly high-quality OCZ unit I can't see it failing, not with the relatively moderate load I was giving it (Q6600, 2 HDD's (IDE, SATA), 6GB DDR2. and GTX260) at least.

Also opinions on new gear would be welcome as I think it's time considering I've just started my dissertation and I don't want to have gear which could potentially go out at any time and have no warranty.

I'm looking at either getting an AM2+ board and an X4 2.5Ghz for the moment, that way I can use 4GB's of my DDR2 and upgrade later onto an X6 black edition and 8GB's of DDR3. Would I see a significant lapse in speed going to an X4 from a Q6600 2.4?

[DanielWray]

Olson: Thank you very much for recommending a PSU tester, I bought one today and tested my PSU.

Every light apart from the -5v LED came on when I plugged in the 24-pin (Main + 4 pin) connector so I can safely assume it's my PSU that is broke, right?

Hopefully nothing on my machine will have been taken out, If someone can give me some more information on what the test result means (I know it means the -5v wire is faulty), but what does this mean overall. Is the -5v something that effects the CPU or RAM directly etc.

Thanks again :)

[olson]

Olson: Thank you very much for recommending a PSU tester, I bought one today and tested my PSU.

Every light apart from the -5v LED came on when I plugged in the 24-pin (Main + 4 pin) connector so I can safely assume it's my PSU that is broke, right?

Hopefully nothing on my machine will have been taken out, If someone can give me some more information on what the test result means (I know it means the -5v wire is faulty), but what does this mean overall. Is the -5v something that effects the CPU or RAM directly etc.

Thanks again :)

If everything checked out except for the negative 5 volt line then the power supply is good to go. In fact your power supply may not even have a negative 5 volt line as it was only used for a few things prior to 1995 like ISA slot cards and early floppy disk controllers. The motherboard is likely the culprit. Processors and memory very rarely go bad unless you let them get way too hot or put way too much voltage through them, both usually from overclocking attempts. A replacement motherboard may or may not be worth it at this point since the system is pretty old.

[DanielWray]

Ah I see, well yea I'm thinking replacing the motherboard is going to be tricky as I can't really find any boards with 4 DDR2 slots and also they are budget models by Asrock which I've heard aren't the best.

I'm thinking of just picking up this is a replacement for the time being, I could always upgrade to 8GB DDR3 & an AMD x6 1090T at a later date so it doesn't sound so bad, unless of course Gigabyte boards are bad quality?

Overclockers link (http://www.overclockers.co.uk/showproduct.php?prodid=BU-187-OK&groupid=43&catid=2047&subcat=)

It's cheap, and it'll probably just be able to cope with some of the work I'll be doing but I desperately need a working machine at home (dissertation.. final year etcetera) so I can use my Linux set-up.

[gelfie]

This happened to me when my BIOS chip died.

Required a replacement motherboard.

[DanielWray]

I've purchased a new motherboard + CPU + RAM combination today.

It was a damn impulse buy and far from ideal but it seems to be working up to now, so hopefully it was just my motherboard giving up and nothing to do with any other components.

Thanks for all the help guys, it's much appreciated!

:beer:

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