Dp46849 Screen goes black after 10-15 minutes

This info was given to me by a HAM Radio friend that repairs TV's For a Living.
Disassemble TV, clean all boards from dust, unplug/replug all connectors,
most are really small, be careful, try TV again. Out Same Model TV started off the same, RIGHT bottom of screen/shadow when TV was on for awhile, since then has got worst, like 2 shadow boxes showed up, now upon startup, TV is screen is covered w/vertical lines, shut off the TV once or twice and works fine until next startup. If the above does not fix TV, look at the top of TV from Back Panel Off, Top-Center is a board called T-Con board, replace it. All the info for this board replacement is on the Bar-Code Laabel and Board itself, ie; T370HW02 VC CNTRL BD, 37T04-COG, FX-5546T03C22 (orC21)-964-0000NMP-00629-03 this board is Mgr By AU Optronics. GoTo For Parts/Pricing, they have 180 warranty on parts, aprox $45.00 for T-Con . http://www.shopjimmy.com/auo-55-46t03-c22-t-con-board.htm. He stated It IS Very Rare That The LCD Screen Itself Would Be The Problem. Right now I have Our Sanyo DP46849 apart
laying down on a bed, had to remove Base Pedestal to remove back cover,
There is a smaller cover, 2 screws u can remove to gain access to the turner board and power supply, there are 2 more boards hidden, before u remove back cover from front panel, untape wire leads from back of LCD Screen and unsnap the 2 torrid coils, black plastic things wires going through, these torrid/ferrit coils are mounted on a snap-in base, w/very small screwdriver they will unsnap from plastic base in 4 corners, if the base breaks from panel frame, just hot reglue back in place when are repairs are final. The 2 panels will seperate eaisly, if not you have some maore screws left to remove. Our TV was little dusty inside on the power supply board and alot of dust collected on some big transistors, 3 lead/legs, I'am hoping this caused the power problem @ start-up, going to clean all bard then reconnect all leads/cable, ect and retry, If no work will replace the T-Con board. Hope This Help's All