Our DLP Mitsubishi we bought in 2005 will not stay on. I at first thought it was the cable/DVD connection but it happens even if nothing in plugged in. It happens after a few seconds to minutes--but it seems to be getting worse. I will turn it on, and a varying time later the TV will either just turn off or display the blue screen then a second later turn off. I tried the troubleshooting and did the system reset, and tried a new outlet, but no success. Any reason for this? It is a bit old I know but not used very hard. Is it worth repairing? Thanks!!