Elite Motherboard and Duron 1 gig

Help! I'm quite new to PCs at their most basic (i.e. when they're still in pieces) and I'm struggling with the following problem. Having put together my system with great care it will not boot up. The motherboard is an Elite k7s5a and the processor is an AMD Duron 1gig. I checked the AMD site to confirm compatability, given the changes made to the processor, and the board, chipset and bios are all correct. The physical installation seems to have gone ok but on powering up all I get is the fan going round, the Relysis 12xDVD busy light flashing, the MAxtor hard drive spins for a few seconds and then the internal speaker beeps a number of times before the computer seems to restart and once the same series of events has happened again everything goes quiet and the computer does nothing else. I've tried to contact Elite but they've not been at all helpful and I don't really know what to do next. Any help would be much appreciated (mostly by my wife who is losing patience with me) Thanks in advance

Test your power supply. I thought I had a problem with this board when really the PSU i got with my case was faulty. See if you have another comp or a friend with a PSU you can steal for a minute and see if it posts with that. What really fooled me was the CPU and graphic cards fans went on but it still didnt post. Took me forever to figure out its the PSU.