Here is a list of steps to try to help fix your issue:

1. Check the batteries in your remote to make sure they are still alive.
2. Update the firmware of your TV and your universal remote.
3. Make sure your TV and remote are within 30ft of each other.
4. Check that the universal remote is compatible with your TV.
5. Re-sync the universal remote to your TV.
6. Unplug the TV and universal remote, leave them off for 30 seconds, then plug them back in.

Follow these steps and you should have your universal remote up and running with your TV!