I have a 55 inch Mitsubishi medallion 1080i and it will just shut off however the green power light stays on..I've reset it a couple of times and I can turn the tv back on and sometimes the screen is blue and sometimes black and sometimes it works...then in a few minutes it shuts off again

I had the same exact problems. So before you go poay a repair person $800 to tell you it is the capacitors. It is simple to repair yourself. Total repair costs will be abouyt $60-$80 plus the time it takes which it took me approximately 2 hours. Now I am good with computers and electronics overall but I looked the how to reapirs up online and it was quite straight forward without any exstensive issue causing work. The main thing is rounding up the capacitors which in my case were found at radio shack as well as all the other items you need. To find out the details on repairs you need to type in "how to replace 55 inch mitsubishi medallion 1080i capacitors. I dont have the details or web page I used still around to referencew you to or i most certainly would. Hope this helps.