Computer won't POST

[Grudge]

Ok, so my trusty old bucket decided not to start properly this morning. The first time I turned it on it started loading Windows, but when I started logging into my account it just stopped and did nothing. There was power, and all the fans were running, but the HDD didn't do anything and there was no signal from the video card.

I shut it down and started it up again, and this time it didn't even get to loading the BIOS, it just beeped once and then shut down. There was still power on the motherboard, the status lights were ok, and the power light was on, but everything was dead - no fans no nothing.

Every subsequent attempt to start it up again has since ended in it either just doing nothing (not even seeming to load the BIOS), only just sitting there, power on (all fans running), but no HDD activity and no signal from the graphics card, OR it just shut down after the first beep (like 3-4 seconds), still having power on the mother board, but all components and fans powered down. It's like a 50-50 chance of either happening.

I've checked that all power connections from the PSU are securely attached, and because it was slightly overclocked I cleared the CMOS, just in case, so it shouldn't have anything to do with that.

So, I'm guessing it could be any of the following:

1. PSU failure, it doesn't deliver the correct voltage on some of the rails.

2. Motherboard failure, could be anything, a faulty capacitor or whatever, hard to find out what's wrong.

3. CPU failure, it's been slightly overclocked for the past 2 years, but the temperature has always been around the 50C line.

I've got an old PSU in the attic, I'll bring it down tonight to see if it's the new one that's broken, other than that I don't have any spare components to exchange to check what's wrong.

Does anyone have any other ideas?

Maybe it's just time to retire this old thing now, I was planning to wait for the new AMD socket to arrive first (Q2 2006), so the timing is not ideal, but if it's the MB or the CPU that's broken, there's not much choice.

Oh, and the specs:

AMD XP2400+ (OC'd at 2083MHz)
2x512 MB TwinMOS PC2700 DDR RAM
Abit NF7-S AGP motherboard
Sapphire Radeon 9800Pro 128MB
Seagate Barracuda 80GB IDE
Antec Sonata II w/ SmartPower 2.0 450W PSU

[Doombrain]

BIOS batt dead or video card?

[shadd_]

try one stick of ram or the other for starters.

[Doombrain]

turn it upside down on a full moon

[Tormentius]

Sounds like the motherboard is on it's way out.

[Grudge]

Thanks, yeah if it's the graphics card, RAM or the cpu, the BIOS should start beeping as soon as I turn the thing on, but now it won't even go that far.

I'm gonna go home and try the other PSU now, but I'm afraid I'm going to have to put a big dent in my wallet tomorrow.

[Underpants?]

try one stick of ram or the other for starters.

this is on track, if that doesn't work, try booting sans ram, pci/agp/other cards, drives and CPU

[Grudge]

ok, seem like it's most likely the PSU. I can start up Windows now with the old PSU, but it did shut down a couple of times before it started working.

This PSU isn't even 6 months old ffs, one would think that it would last a bit longer than that?. Funny thing is that our dev server at work blew it's PSU last week. And what brand was it? Also an Antec. Perhaps it's time to change to another brand.

[Oeloe]

Hmm, i'm having trouble with an NF7-S (cold boot problem and sudden reboots) and an Antec 350W PSU. I used this PSU with another mobo as well and perfectly stable though. I'll try another PSU though, to see if the cold boot problem is gone then.