Over the weekend I tried to replace a RAM card that I had broken. I went to Tiger Direct to buy a new one. Instead of matching the Kingston 2GB card I still had in my laptop, they gave a a 4GB Kingston card, for a total of 6 GB of RAM. After I installed it, the screen would not come on. Is there anything I need to do in the BIOS to get this to work? Is it a mismatch of gigs that is causing the problem?