I NEED TO RUN A CHANNEL SEARCH ON MY iNSIGNIA T.V.

stop pushing buttons your not sure of.
To perform a channel scan using the coaxial input:

Press the INPUT button on your remote to view your current input source. ...
If the TV input is not selected, press INPUT until the TV input mode is selected.
Open the on-screen menu and select TV or Tuner option. ...
Highlight Tuner Mode and select the correct option:

Refer its user manual for details.

Auto channel search is how your tv finds channels that are available. Under settings in the menu should be initial set up. There you will find channel search.

You will have to Bing the remote model number and see what units are available for codes. Or run a channel search one at a time.

Refer its user manual for details.

you have to be on the Cable/Antenna Input. Then you can access the menu option to auto search for you channels again.

I have one of the same tvs. Start by going under menu,setup,tuning band and set it up for antenna. When you get that far put in auto channel search. To see how to get best reception where you live go to http://www.antennaweb.org

Comment if you need any further help

Set your television to channel 3. Then power on your Insignia unit and run the auto-search function as described in the user manual found here - http://www.insignia-products.com/skins/skin_1/Topics/Documents/07-576_NS-DXA1_WEB.pdf