TV turns itself off after a few seconds, no picture at all

If he replaced all the internal boards win with a known good boards then it sounds like there may be a connector loose or not even connected up.

hi there,

Check for bad solder on convergence module. May have bad stk's. Do not neglect looking for bad solder on dsignal and defl boards. Mitsubishi is very prone to bad solder.

`jack

the relay is the safety protective device..sometimes a defective component or something. maybe an overloaded power supply might caused this problem..so before any thing could gets worst..the relay will shut the unit..

it has problem in picture tube

Bad caps in the power supply must be replaced .

my tv will not come on

I need to know how long do you have the tv?In the other word,approx. how many hours you have put into it?
Secondly,did you wall mounted the tv or setting it close the the area which there is not much room for the back of your tv to breath?
solutiondoct

I had a similar problem with my Phillips 42 in. LCD HD TV.

Here's the problem. The Power Supply Board. I opened my TV up(warranty was up of course) and found several bad capacitors. Phillips and several other companies were sold capacitors that although were highly rated failed within 5 years because of a lack of preservatives. All sorts of electronic equipment is now being effected due to these defective capacitors.
Solutions?
1. Take it in and have it fixed
2. Open it up, check the board for faulty capacitors(bulged or leaking) Buy a new Power supply board and install it.
3. Remove PSB, remove faulty capacitors and replace with compatible new ones.

Hope this helps

THE POWER SUPPLY OF YOUR TV WAS THE PROBLEM,YOU COLD SOLDER THE MAINBOARD OF YOUR TV,AND THE CRT SOCKET CONNECT TO THE TUBE IS ALSO COLDSOLDER,.

As far as fixing goes, you might as well get a new TV... Unless its a LARGE EXPENSIVE HOLY $%^# TV, It will cost more to fix, than to just buy a new one, unless its under warranty, which being an older model as that (or so im reading) It may not be covered.

Try unplugging the TV, and while unplugged, hold down the power button for a full minute (yes, with the plug NOT in the wall) after a minute, plug it back in, and try. Its a hard reset. If it still does not work, and you've tried different outlets, It's probably a repair issue, and you'll need to get someone to fix it, or just junk it :-/