Samsung DLP Cuts out after a few minutes w/ buzzing noise

This problem has been happening off and on recently. When i power my system on, a picture will appear for a few seconds, then go black. I can hear a buzzing noise coming from the TV and it tries to restart its self. If i unplug the power cable, and let it sit for 10 mins, i can turn it on and get a picture, but it goes black again after about 20 seconds, and the buzzing starts again. Sometimes (if i'm lucky) the picture will come back.

I have replaced the bulb twice on this unit in the 4 years i have had it, so i don't think that is the cause. Could this be the color wheel?

Thanks for your help!!

Color wheel is shot, go to Google Jangro, and see how to install one
yourself and save some bucks. There is a new better color wheel
than the one that came with your dlp. I have quite a few post in
there myself...