I deal with these stupid data/video projectors very often. Most problems stem from blocked air vents, clogged with dust or not enough fresh air supply. Make sure all air vents are not full of dust. Also look at the proj. lamp closely. If the element looks swollen or has a build-up of salts (or similar) on it, that's a good indicator the lamp is failing. Often the lamp ballast circuitry also weakens/fails over time and that will cause the proj. to not illuminate or shut down after a few minutes of use. Also, if projector has a lamp hours reset feature, try ressetting that to 0hrs. Sharps were known to shut down after 900-1000hrs of lamp use. After a reset of that feature, they work like a charm. Dunno of this Sony is like that as well. Check your proj's menu settings for things like "power off /no signal" ect. If no signal or a static video image is detected for a specific time interval, it will shut down (that is if your projector has that feature.