My mother in law turned off her 32" lcd hdtv emerson now it turn back on

SOURCE: What kind of HD output does Emerson LCD HDTV have?

The TV resolution is 720p

SOURCE: it being emerson 32" hdtv lcd turns on but immediately turns off

This is Emerson's #1 problem.
The Inverter Transformer on the power supply/backlight inverter board goes bad. It's what powers up the screen for your TV. When the part goes bad, it doesn't have enough juice to power the screen and the TV automatically turns off. You have 5 Inverter Transformer on your board.
You can fix the problem by replacing the whole board or replace the bad Inverter Transformer.
Here's where you can get a new board for a good price:
http://www.shopjimmy.com/catalogsearch/result/?q=lc320em9+inverter

Or, here's where you can get replacement Inverter Transformers:

http://www.partstore.com/Part/Funai%20Corporation%20Inc/Funai/LTZ2PC0MS008.aspx

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

SOURCE: Emerson TV LC320EMXF Remote code for Direc TV

I got the same TV for my stepdaughter and had the same problem. None of the Emerson codes worked. We use Dish Network but I did the autoscan thing on the remote and found that it was 672 which is listed as a Sylvania. I don't know if it will help in your case but maybe try the Sylvania codes. Good luck.

SOURCE: Tv turns off a second after I turn it on

Just repaired this actual model.
remove the back of the tv. Loof at the circuit board on the left as you face the back of the tv. In the middle there is a diode that burns out. Remove all ov the screws holding this circuit board to the tv. Carefully unplug all of the connections and flip the board over. See that the number on the back side of the board by the burnt diode is d1940. Have the diode replaced by a competent repairman and oberve polarity. put everthing back as you found it and try the tv. You may want to have a fire extiguisher nearby.