Diagnosis
The opener lost its learned remote codes. The 54930 uses a fixed code system with DIP switches.
How to Fix It
Match the DIP switches on the remote to the opener. On the opener head, open the light lens cover. Find the bank of 8-12 small DIP switches. Set them to the same pattern as the switches inside your handheld remote. Close the cover. Test the remote.
If That Didn't Work
The remote battery is dead. Replace the battery (usually a 9V or 12V battery). Press and hold the remote button while pointing it at the opener to re-sync.
Heads Up
Fixed code systems are less secure. Anyone with a remote set to the same code can open your door. Consider upgrading to a rolling code keypad for better security.