My TV won't turn on, but when it does it turns off within the next 30 seconds. Sometimes it with turn off, on, and then back off again all on it's own... What is this? What should I do? It's a Samsung by the way.

What model? There could be any number of things. A bad IR board, touch function board, main board, power supply (some model Samsung LCDs are known for bad capacitors on the power supply, which cause the TV to not turn on and to hear the relay clicking constantly or cause slow start up times, etc). Could be just as simple as the remote being held down or bumped (or a secondary/spare remote).

It's a Samsung. Sometimes it works fine while others it just doesn't.

What model is it? We have what make... but what model? You already told us it was a Samsung. The model should be something like LN-40A550 or similar. Depends on size, year, and series.

It should be printed on the side of the TV, but if it is not, then it will be on the back.

LN32A450

2008 is the year

When it turns off, do you hear the melody? Does it turn itself on randomly?

It sounds like it's a capacitor on the power supply. That is one of the models that is known for this issue.

If I recall correctly, there's a 10V 2200μF at CM861 on the power supply. Replacing it with a 16V 2200μF capacitor should fix the issue. I only recommend doing this if you are comfortable with electronics.

Otherwise it shouldn't be expensive to have someone fix it for you. It would probably be around $150USD for GeekSquad to fix it.