If your remote is too far away from the receiver, it will not work.
A remote-control garage-door opener is a handy little electronic device that makes it possible to get into the garage without leaving the car or heaving up the heavy door yourself. The opener remotely sends an infrared or IR signal to a receiver that triggers a switch, promting an electric motor to open or close the garage door. Before any garage door remote works correctly it must be within the specified range of its IR signal-sending strength. If it is within range but still does not work, there are ways to fix it.
Check the Batteries
The most common cause of garage door remote control failure are weak or dead batteries. To be sure that the batteries are always good, use name-brand quality batteries instead of discount brands. Also, although using rechargeable batteries is environmentally friendly and cost effective in the long run, they only put out approximately 1.2 volts as opposed to an alkaline battery that puts out 1.5 volts. Therefore, a remote powered with two rechargeables would only get 2.4 volts when it is designed to run on 3 volts of power. This 25-percent lack of power may seriously compromise the range and effectiveness of the remote control unit.
Check the Battery Contacts
Dirty, worn or wet contacts inside of the battery case inhibit the electrical current of the batteries from fully reaching the circuit board inside of the remote control. If the contacts look discolored, pitted or are wet, they need to be dried and polished before any battery can successfully power a remote control. Contacts can be polished with a fine-grit sandpaper, like 400-grit or fine steel wool.
Clean the Eyes
The plastic covering over the IR unit on both the remote control and the receiving unit is called the eye. This "eye" allows the IR signal to pass through it in both transmitting and receiving. Eyes can be wiped off using a soft damp cloth. Most remote eyes are made of plastic that, although resistant to scratching, become scratched if rubbed against metal, abrasive fibers or dropped onto the ground. The plastic can be polished using specialized plastic polishing substances, but if the IR eye on a remote control is badly scratched, pitted or gouged, there may be no recourse except to get a new one.
Reset the System
Remote controls and receivers are small computers. Sometimes a reset is needed to reboot the circuit boards in both the remote control and the receiver. A reset is accomplished by removing the batteries in the remote for approximately 30 seconds and re-installing them. A reset on a receiver is accomplished by unplugging the unit from the wall socket for a bout 30 seconds, then plugging it back in.