I have been plagued with this also. My six year old $1000.00 Sony started acting up this summer and I had in the shop twice, no easy task to say the least. This time I went out shopping for a new TV since it was getting near impossible to get this thing to stay on. My problem was that it would come on and in about 30 to 90 seconds it would go black (audio stays on) I tried to buy a Toshiba yesterday (best ratings but can't compare to Sony in picture quality. none of them did in a side by side comparison, but I didn’t want to buy another Sony) I tried to buy one at Best Buy. I say tried to buy but because of the Super Bowl (Go Steelers) they could not deliver it till next week. After searching from store to store I finally found the Toshiba at Sears and they were $45.00 cheaper and could deliver it this week, but when we wrote the order up they were back ordered...Arrruugghhh! Well the good Lord was watching over me and my $600.00. I got home and got on the phone again, calling TV repair shops and finally got a fix! Here goes... Sony has a default override that disables the video whenever something is not 100%, that’s why the video shuts down; acting like the Picture tube is bad. I was told to look for the G2 adjustment and turn it. He said it was a black plastic screw adjustment located on the picture tube yoke or on the high voltage?? That can be found by following the big red lead that goes from the Tube, to it. I found it on mine and there are 2 screws, the top one (if you look closely) says focus the other one (the one you want) says screen. As the set was on (audio fine as usual but no video) I just turned that stupid screw a hair clockwise and waa laa Picture on! I played with it to see what it does and if I turned it full counterclockwise the screen went black, as I slowly nudged it clockwise I got a line at the top off the screen, then a good picture, then all the way up, a sort of bluish picture with faint lines. I backed off the screw and turned it to where the picture came on and then just a hair to keep it on, but not so far to get the lines and left it there. Another thing this wonderful TV tech told me was .Sony has a chip that automatically sets the red, blue, and green every single time the set is turned on. I'm glad I remembered that because there was lower right green cast, and an upper right blue cast after messing with this screw. I shut the set off and turned it back on and that was corrected : ) I turned the set on this morning and it was perfect and stayed on unlike the last two weeks of banging, plugging and unplugging, and shutting off and on numerous times to get it to stay on for the night. It seems that all my set needed was that tiny turn of that screw that fixed my set and saved me from spending $600.00 yesterday and throwing my perfectly good Sony TV in the dumpster....Yes, Praise You Jesus!

My picture was blue. One quarter turn of the black screw and problem solved...Thanks!