I have the same issue as do many others, with all different models and types. It is inherit with Phillips and they just keep selling them. If you are within time to return it, that is what I should have done. There are a number of posts here on Phillips, try a search on this forum.

my 50" magnavox/phillips hdtv did the same thing for several months. now it won't come on and the LED light blinks when tv is powered on. tv repair shop says its the "main power regulator" and will cost me $1700 to repair. The tv didn't cost $1700 to begin with.

And I have the same problem as well. Started out only a few hours at a time, but now it shuts off every couple of minutes. A friend of mine had a similar issue with his TV (not Philips) and he was told to open it up and adjust the screws that control the coloring. There were three sets of three screws (each set a different color). Aparently, in his case, the "blue" was sending too much power into the TV and it was shutting it off. He adjusted the "blue" screw just a hair and said he hasn't had a problem since. Again, it wasn't Philips, but maybe we all have a similar issue. I just opened up the back of my TV (with a torque screwdriver) and I haven't been able to locate any screws yet. But I'll post any updates as I see them.

Can't find any screws. Anyone know what can be adjusted back there without bringing it to a "guy" for a million dollars ?

I think I've figured out the problem ! I hope this reaches you all.

I noticed that when I got the TV (in the winter season), I never had this problem. The TV was working great. But as the temperature got warmer and warmer and the humidity got higher and higher, that's when the problems began. When I put the "temperature theory" to the test, although I thought it was a long shot at the time, I had great success. I thought, "what if I just tried to keep the TV temperature down ?" So I put a small desk fan up against the left side of the TV, aimed it toward the inside (through the vent) and put it on full blast. After about five minutes or so, I turned the TV on and it STAYED ON ! (The left side of the TV is where the over-heating power regulator is located).

As I did this on a regular basis, I had nothing but success. Few things:

#1 - Turning the fan on five minutes ahead of time turned out to be irelevant. Nowadays, I just turn the fan on 'high' just before I turn the TV on.

#2 - I have no air condintioning in my living room, so even though I have this fan, the TV will still shut off occasionally on really really hot days. I did, however, purchase one of those window fans and installed it in the closest window to the TV. This helps. Less light is getting in, and it's a bit cooler by the TV.

#3 - The desk fan that I have is very small, but quite powerful for it's size. It's white and made out of tough plastic. It's about 8 1/2 inches across and 10 1/2 inches high. It's made by a company called HOLMES.

I hope this reaches you all, and I hope you have the same luck that I did. We all probably spent a lot of money on this TV, and because Philips is being a douche-bag about it, we have to make due with what we have. Let me know if you have any questions. Good luck.