I had a motherboard die recently and received a replacement. I had the same symptom with motherboard #2 and my processor, an Athlon 3000 XP. I guessed that OK, the processor must be dead and the boards were OK. Strapped for cash I bought a mobile 2600+ . It also did not work with motherboard #2. Now I conclude that CPU #1 killed 2 mobo's. Nice. I bought the cheapest motherboard I could find, an MSI KT4AV-L . Luckily my new CPU is alive, but even better, it overclocks easily on air. The board runs 15 x 160 all day long on normal air cooling (running a Volcano 9 at 4500 rpm at the moment) and it rarely hits 125 degrees F. This board does not support a 200 FSB, nor does it support dual channel RAM. Changing the vcore does absolutely nothing, so I'm running at the board's default 1.55 volts. I'm sure their are tons of better setups and yes, I didn't do squat to the setup to get it to run. No uber water cooling or anything impressive, but I'm pretty sure the combo will beat out a 3200+ on the cheap. I believe everything we've heard about the low voltage mobiles XP's it true.
Bill
Bill