I have a kind of a weird issue here. First off, I was building a computer for a friend(will be his first system) and I had a budget in mind so I found an Athlon XP 2500 figuring I could overclock it and make it respectable for pretty cheap. When I got the thing, I plugged it in to an Abit KD7A and booted it up and messed with it a little to get it running at 2.21ghz. It seemed stable and I used it for about an hour (I had already installed XP with a 2200+ I had lying around while I waited for the Barton core xp). Then I took the heatsink off because I didn't put any thermal paste on the cpu. I kept a close eye on the cpu temp when it was overclocked and it never got above 130 degrees fahrenheit(~54 C).
Now, here's the problem: after I put it all back together and rebooted the computer acts like the cpu is bad. The hard drive LED stays solid and all fans spin, but nothing else happens. Not even any beep codes, but then when I reset the CMOS the computer boots and the bios reads the cpu as an Athlon XP at 700mhz. Every time I change it to anything else, it goes back to not booting up and just gives the solid HD LED and fans spin.
Now here's the kicker, I took the CPU out and put it in another motheboard(a DFI KM400-MLV) I have and set it to auto FSB, it reads the cpu as an Athlon xp at 933mhz. Both cases seem to have a multiplier of 7, which makes no sense at all. I don't know if I shorted something with the thermal paste or what, but I'm lost. I have tried different combinations in the Abit soft menu(voltages, ratios, FSB's, and multipliers) with no luck. If the CPU f'ed up, would it just not work at all?
I'm open to any ideas, here's a little more information on the rig:
Nope, I learned that lesson with an AMD K6-2. I tried to boot it up withoout a hsf real quick to look at a setting, and burned the crap out of my fingers. Didn't fry that cpu, though. But I do know how hot they get and how quickly they get there.
Generally athlons run default underclocked, in my experience, although not that low. Make sure your FSB in the bios is at the right setting, not sure what your motherboard supports though, but im pretty sure you would run that at an FSB of 333, if not, 266.
edit: researched, it should be running at 333 with a multiplier of 5.5
edit: i also didnt read that you said you messed with the settings either. sounds like you have a dead CPU on your hands. what kind of power supply are you using? you can get REALLY cheap semprons and 754 boards and they overclock quite nicely, if you're looking for something budget. ive personally got a sempron 3100 oced from 1.8ghz to 2.6.
Power supply is an Xpower(I think) 450 watt. I did some research and each line rating should be plenty to do some decent overclocking. I did notice one thing I didn't mention yet, a couple of times after resetting the cmos, I've noticed the cpu voltage sets itself to 1.85V, which might be dangerously high(?). But most of the time, it's at the 1.65V it should be. Still, has anybody had a cpu die that will read at a super low speed?
I've never heard of Xpower before, while the amperage may be enough, I would look into efficiency and reliability of that power supply. General rule of thumb, the heavier it is, the better it is. 1.85 is not dangerously high, since its stock 1.65, but you don't really want to go much higher. I would definitely look into another power supply and perhaps use another chip. power supply is the one thing you do not want to cheap out on, considering everything relies on it. Some brands I would look into, FSP Group/Fortron, Enermax (I'm using one now, and I've used 2 FSP units), PC Power and Cooling (high end, expensive), seasonic, some OCZ units (research first, but usually they are rebrandings of FSP). Theres some others out there, google around for them.
anyway im rambling on, and you probably already know this stuff, lol.