My 32 inch emerson powers up and cuts off after a few seconds.

Hi, I own the same TV and had the same problem. It's the #1 plaguing issue with flat panel TVs made by Funai corp. Emerson is made by them. Normally, when this happens, the TV goes into " Protection Mode " because of a failing circuit board.

The most common thing to go out on flat panel TV is the circuit board that supply power to the screen. Commonly called a Backlight Inverter Board. But, I can't say it's 100% the problem because I can't actually look at the tv over the internet. I can only make guesses with the symptom. I'm willing to bet you have the same problem like mine. One of six Inverter Transformers when bad on my Power/Backlight Inverter Supply Board. I replaced it and it works fine again.

You have a few choices:
1. You can try leaving the TV unplugged for 30 minutes so the TV can reset itself.

2. If you have some electronic experience, if you can find and purchase a Service Manual at Tvtechcenter.com: http://www.tvtechcenter.com/xcart/search.php?mode=search&page=1 It will help you diagnose the source of the problem and fix it by soldering in the new part. The Service Manual will give you circuit diagrams, test points, and part# lists.Usually, cost under $6. And most cases the new part cost less than $15.
http://www.partstore.com/Part/Funai%20Corporation%20Inc/Funai/LTZ2PC0MS008.aspx

http://www.encompassparts.com/products/?LTZ2PC0MS008

3. Pay a TV shop to do the repairs. It maybe costly, but get an estimate of how much they will charge. That way you can decide if it worth repairing or replacing the whole TV.