you need to find out what cpu you have, p3 or p4.
also unplug your cdrom power supply. then try booting it up.
although you must have some knowledge of builing/repairing a computer. if you take the side panel off your rig you will see what is happening in there a lot better.
make sure the power is disconnected before you do anything inside the p.c.
PENTIUM 4 3.06 GHZ WITH HT TECHNOLOGY