I'd recommend having the unit inspected by a technician. The buzzing noise may be due to the color wheel or other part, and will likely break down before it fixes itself. If it's turning itself off, it's designed to do that to prevent damage. Something is going on, and it's recommended to have the unit inspected.
I have a 46" Samsung DLP (HL-P4663W) which I purchased in 2004. It's been only 6 years and it started to make loud buzzing sounds to the point where we had to turn up the volume, but that wouldn't help either. Just recently, after maybe 15 minutes of buzzing, the TV just turned-off itself. I waited a few minutes before turning it back on......still buzzing noise, then in less than 4 minutes, it turned itself off again. What is the problem and how can I fix this myself? What do I need to do?