Having a major problem.

The other night I was playing GTA2 and left it on the PC for about an hour. When I returned, the game had locked up, so I restarted. Upon restarting, my vocal post said "CPU failed due to overclocking." After restarting again, the screen went inactive and my post only said, "system failed memory test," and then proceeded no further. It has been over 2 years since I first built this PC, so I just thought the thermal paste had worn out.

The next day or so, I completely dissect my PC, give every piece of hardware and my case a thorough cleaning; I also remove, clean and reseat my CPU and heatsink (using Arctic Alumina thermal paste) and just make everything look brand new. After completely rebuilding my case and getting everything hooked up and ready to go, I turn it on for the first time.

The screen still stayed inactive and reported "system failed memory test," again going no further. Just like before, all of my fans work, my mobo green light is on, and everything appears to be normal on the outside!

1. I then proceeded to remove all 3 of my DDR DIMMs and insert a lower-frequency (PC2100) stick that I know works. I also tried my RAM again in single configurations. Same results.

2. I then replace the video card. Same results.

3. I tried a new, more powerful PSU, no change.

4. New monitor? Same problem.

5. I tried clearing the CMOS by removing the battery and resetting the jumper, no change.

6. I tried moving my board out of the case onto a cardboard box, still the same results.

My hardware spec.'s are as follows:

ASUS A7N8X Deluxe Rev. 1.04 (1007, near-latest BIOS)
AMD Athlon XP 2700+ (333 FSB Thoroughbred core)
Thermaltake Volcano 9 (Socket-A heatsink/fan)
Corsair VS DDR333 (PC2700) RAM, 1024 MB (512 x1, 256 x2)
PNY Verto GeForce 4 Ti 4600, 128MB AGP 8x (Nvidia, of course)
Western Digital 7200 RPM 120g PATA HD (single drive)
2 Optical (DVD) drives

I suppose the only thing it could be is a dead CPU and/or mobo. Soon I will test an old K6 Socket-A CPU to make sure it isn't that. Any suggestions? I googled this and tried all the results/suggestions I could find but to no avail. It just seems weird to me that the CPU would suddenly die with no tampering. Even if the paste had worn out, my mobo has built-in protections to prevent a heated death. If the CMOS battery is dead/low, could that be the problem?

I am just at a loss now, please offer any suggestions! Thanks.

Unfortunately you're missing the ability to perform the one test that's gonna be of any REAL use to you. You don't seem to have a second motherboard/processor to cross-compare. If the system doesn't start with known good memory with nothing connected except motherboard/video/memory/processor, then you're (a) in trouble, and (b) despirately in need of another board/processor to compare.

Speaker connected? Beeps or LED indicators?

Yeah, you're boned.

I had a Soyo Dragon Platinum that took a great dump one day. At least I had a pile of other Athlon systems at the time, so I didn't waste time figuring it out :(

I've yet to put that old Athlon 1.4 Ghz in there, that will at least let me know if I need to RMA the board (still a year left on the three year warranty). It's irritating that a performance (well, at the time) motherboard would die after two years. :(

Sounds like a similar issue to what i had a couple of month's back on a board of roughly the same age. Spent days trying to work it out and finally discovered that the capacitors on the board were dead.

Look very closely at the tops of them all to make sure they are not swelled or cracked, if they are, you are screwed.

Have you tried sniffing your mainboard? I know it sounds silly but does anything smell burnt? Sorry man :(

Ah yes, I forgot to mention it but one of the first things I did was check the board's capacitors, expecting to find one blown or leaking, but they all look stellar. Nothing smells burnt either =).

By today I'll know if it was the board or the CPU. If the CPU, then I'll probably use this as an excuse to upgrade to a 3200+ and see what I can do about redeeming AMD's 3-year retail warranty. If the board, it will have died in style and I'll salute and then RMA it.

Even if worse comes to worse and ASUS blames me for any damage to it then they'll just charge me $60 for a replacement. The major cost to me is the inconvenience and irritation.

Thank you all for your condolences and suggestions! :o

Plugged in an old T-bird Athlon today, my motherboard still works!

I guess what happened is when the thermal paste (was low quality stuff.. I didn't know of any alternatives at the time) deteriorated too much on my XP 2700+ my mobo didn't have time to prevent the core from frying.. oh well. I've had my eye on a 3200+ for a while anyway. I will also do away with that terrible, noisy, abusive Volcano 9.

I'm assuming that since the core is fried on the original CPU my 3-year limited warranty is no good :o .

Well good news is you know the problem but bummer on the warranty. Good luck, I'd go apeshit without my PC I can only imagine what you're going through.