2007 iMac Blurred Screen of Death

Hi, I'm running an intel based iMac with 4GB of ram, and am running OS X 10.10.1. I have recently encountered a rather large problem. I have been attempting to boot, however nothing will respond. I have reset the NVRAM and the PRAM, and it will no longer recognize that there is a keyboard connected. I have attempted to boot into the Recovery HD, however it will not budge. I have also tried to open the diagnostics tool, and that will not work. Please help. I have also reinstalled the RAM.

Thanks.