Upgraged RAM...Now NO VIDEO, NO MOUSE

Hello,
I just upgraged my HP M470n computer. The mobo is a ASUS P4SD-LA with Intel 848P chipset. I removed the 512MB module and replaced it with two 1GB modules. Now that I turn my computer on, the LED light is on and the HD seems to work but I HAVE NO VIDEO!

The optical mouse shows no laser light and the video displays NO SIGNAL. One minor detail is that the latch that I push down on (to pop the RAM memory up) broke on one side, but once I put the module in place, the latch pushed up like the others. Any suggestions?

PS. I did use a ESD strap, and I guess from my movements I didn't notice that it had unclipped.

THANKS A BILLION IN ADVANCE.