The only thing i can think of is that theres some jumpers/dip switches on the motherboard that r incorrectly set......
look in your Motherboard Booklet and match ALL the jumper/dip swtich settings to AUTO-DETECT and/or DEFAULT.......IF that doesnt work, than MANUALLY SET THEM......AKA Set all the jumpers to the specifications of yoru CPU, RAM etc....IF THAT DOESNT WORK..........exchange the Motherboard, becasue uve now gone through 2 different peices of ram, and if the CPU wasnt working, it wouldnt do ANYTHING AT ALL when u try to power it on.......and u say the Video card is ALL THE WAY IN right ??? well......try what i said, if it dont work.......exchange yoru motherboard.......
-MeTaL RoCkEr
My <font color=red>Z28</font color=red> can take your <font color=blue>P4</font color=blue> off the line!