Right, I've got a speaker for the new MB and it beeped constantly, so pulled out the RAM, swapped it for some new stuff. I rebooted it without the DVD drive or hard drive plugged in, with one stick of RAM only. It went to POST. I then put hard drive and optical drive in, and it wouldn't post. I unplugged both of them and redid exactly what I did for it to go to post. It wouldn't post, and there was just a single beep from the speaker which according to the motherboard means all is well. I had a friend come round today and he's well into PCs too (he brought the mobo speaker) and he was perplexed. This is a right tough cookie to solve.