I have had this problem with an Amana. It cost me $75 dollars to fix it.
Here is the fix for free:
The food was pretty packed in the freezer and was brushing against the top of it. On the top is the dial control for coldness and the integrated switch to turn it off.
Mine was off, the opening and closing of the drawer caused the dial to turn all the way down and then to off.
The repair guy came over and turned it on. Didn't I feel dumb.
This may or may not be your problem, but it's something to check.
Good luck with this,
Frank