Tv won't stay on longer than 3 sec.

if you have cable hook up it could very well be the cable and not the TV

Check your remote it may be in a different mode or your wires or cables maybe disconnected also sounds like your auto shut off has been activated

Do the self check when power light goes off.

On front of set press and hold both the menu and input buttons for 5 seconds or longer and release both buttons.

Power light will blink a error code like: 2 blinks, 2 blinks, a pause and repeat about 4 more times.

Let me know what error code you find and I will tell you what it means.

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SD TECH

no, if blink code the problem is in the TV set--cable will not cause this type of trouble

quite possibly the ballast is the problem its not uncommon for the ballast to take the lamp out when it blows out. Have you tried to access the self diagnosis feature to see if there is an error code?

take it back!

my same make tv shuts off afetr so long by itself

tv is in shut down mode ///

TRY REPLACING THE REGULATOR OR CHECK DIODES IN SAID CIRCUIT ,ALSO CHECK FOR BAD CONNECTIONS.

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