My tv shuts off after only two minutes

Try using a master reset to fix this.
Sometimes after being used for awhile electronics tend to malfunction.
press and hold these buttons in this order....
power / volume up / channel down.
The tv should shut off after doing this.
Turn it back on manually.
This will reset the TVs internal memory chip.
I dont guarentee this as a permanent fix....but it worked for me.Good luck

I would try the tv in another outlet, if that doesn't solve the problem the tv should come with a standard warranty and is likely to be replaced (if you got the store warranty, then you may be able to get a replacement or your money back during a certain time period).

You might want to check the programming. The TV can be programmed (for up to 120 minutes) to turn off automatically.