This is a Hunter UC7848. Even if your remote doesn't look exactly like this one, they work on the same principle.
When the buttons on your fan remote control stop responding, or intermittently working. It is very frustrating that the Fan On button works, but the Fan Off button stops responding and there is no way to turn the fan off. . This occurs because the contacts inside the remote are dirty. Once cleaned, the remote responds with featherlight touch.
A new remote costs $32.00 plus shipping. but you can fix it in 15 minutes with tools you have around the house.
Step 1: Opening the Remote
After removing the battery cover and the 9v battery, use a small, thin, philips screwdriver to undo the two screws that hold the cover together, and remove the back cover.
Step 2: Removing the Circuit Board
The board is being held in place with one phillips screw (two actually, the other one is also holding the back cover). Remove the board and flip it over.
Notice how dirty the contacts are.
Step 3: Cleaning the Contacts
Use a pencil eraser to rub the contacts clean. The eraser will collect the carbon gunk from the contacts.
Use a cotton swab with some rubbing alcohol to clean the contacts. repeat until the swab comes up clean.
Step 4: Cleaning the Contact Makers (buttons)
Use a swan with alcohol to clean the black points. Those are made of carbon and rubber and take a while to clean.
Step 5: Assemble
Place the clean board in the body of the remote.
Replace and tighten the screw that holds the board.
put the back cover on the remote and tighten the two screws that holds it in place.
connect the 9v battery and replace the battery cover.
You are done.