My dell E510 will not boot-up completely. It goes to 95% then freezes at the Dell screen. The 1 and 4 leds are on on the front panel. I have tried a few things and nothing has worked ...so far. I have tried to remove the CMOS battery and reinstall after 2 minutes, I have tried to boot-up in setup using F2 and F12 and the keyboard does not respond. I have unplugged all expansion boards and peripherials(no luck). I tried to put the restore cd in the cd drive and boot but it does not go to it and I cannot change the boot sequence because the keyboard does not respond. I removed one of the memory sticks(no boot). I also tried to umplug the front panel and it still does not boot up completely. I also reseated all connectors(no change). I am thinking it could be the motherboard because of the non-working USB keyboard and mouse. Any help would be appreciated.