Why Is My 32 In. Dynex Cutting On For A Few Seconds And Back Off Over And Over?

First of all, check to make sure your TV isn't getting too warm. Make sure it has adequate clearance, that it is not super dusty at the vents bringing in air to cool it or exhausting warm air.  Do you hear any extra noises?

How about your remote - does it need a new battery? A new bulb?  Is it the Dynex remote or the one from your TV service supplier?  Is your surge protector working properly?  Have you tested it on another appliance? Have you tried unplugging the set and waiting an hour before plugging it in again?  Do you have a sticking remote key? Sometimes it is only one key sticking intermittently.

If you've done all of these things, take the model number from the back and contact Dynex. http://www.dynexproducts.com/support.html as the problem could be an internal problem which you will need parts to repair...and possibly a repairman.  Is it still under warranty?

I ask about the warranty because it could be a motherboard, thermal switch, bad fan or a few other things which most of us couldn't or wouldn't try at home. 

Of course you could just have a lemon or an aging set but I like Dynex as decent value for the money.

By the way is the TV actually cutting out completely or are you just losing the signal? If so, is that occuring during wet weather conditions?  In that case contact your service supplier.

Good luck

Since you have the model number, it will be easier to contact Dynex