The tv shuts off by itself and wont turn on for about 30 minutes.

Might be the power supply in TV or one of the boards in it. Depending on TV cost vs. repairing it or getting a new one?

Sounds like your power board is shutting down as it gets hot. I would get prices for and replace the power board!

it looks like the problem is in the 16v line..try to take it apart..and there's gonna be a 2200mf cap leaky.
that will solve your problem.

tv works for about 2 minutes, then shuts itself off. the red standby light flashes 50 times, then the tv. comes back on for approximetly 2 minutes then goes off again, only to repeat again

Sony KV-30HS420 TV shuts off, indicator light blinks 7 times

Hi, Lamp of TV getting weaker and requires replacement. This shut off by itself will increase day by day until you put new lamp in TV. Always Buy Sony original lamp and avoid aftermarket/ cheap lamp for TV safety.

Is your air intake clean or clogged.. Maybe it's overheating causing it to shut off.. Had the same problem didn't replace the bulb but cleaned the intake and it works great again. Worth a try.. Intake is located on the left back pannel of the tv.. outside pannel pops off easly.

check to see if tv is set on a timer to turn off?

Followed Terryfic's solution. I am a DIYer and managed to order the part, desolder the old one and solder in the new one. However, when I turned it back on I got a black screen with sound. Hmmm, saw the adjustment screws but was hesitant. Ended up turning about 10 degrees one way and presto chango... Saved a $1200 upgrade to HD for a $30 part! Thanks

check your sleep timer settings. they stay on no matter how much you turn your unit on and off.