Okay, I'm asking these questions to isolate and narrow down the problem.
The first thing you'd want to do, is unplug the TV from power, then press and hold the power button on the TV itself (not the remote), for 10 seconds, then release and plug the set back in. Press power once and attempt to operate the TV. This is a hard reset and can cure this problem often times.
If it does not, then the second thing you'd want to do is have your husband open the TV back up and make sure no cables are pulled loose, or partially off of the Mainboard (the Mainboard is the board that houses the AV jacks on it).
The Mainboard also controls the On/Off, Input, Channel and Volume controls
We need to try to reprogram the remote to narrow down the problem.
Right now it's one of the following:
Controller board (this board actually has the power,channel, volume and menu buttons on it), it's easy to locate you jut verify where the controls are on the TV itself, pull the cover off the back and find the little board that houses these controls. IF the remote is programmed, and once you reprogram the remote it DOES work, then your controller board is bad.
If you reprogram the remote, it does not work, then you disconnect the controller board's plug (follow the wire from this board to the mainboard and unplug it from the mainboard OR the controller board), and see if the remote will work now. IF it still DOES not work, then you have a faulty Mainboard (or a plug pulled loose from the Mainboard- again this is the board that houses the audio and video jack on it. It also generates the on/off, input, channel and volume commands).
This is how we narrow down the problem and the reason for re-programming the remote (or finding the original TV remote, making sure it has fresh batteries, then trying that).
If you need further assistance or links to parts once you've done the steps above to isolate the problem, let me know.
If you're satisfied with my service, please do not forget to rate the answer.