Make sure the projector is not in direct sunlight. Strong lighting, especially fluorescent lights, may affect the projector’s infrared receivers. If you still have trouble using the remote control, disable one of the remote receivers using the Settings menu to block interference from bright light. See Customizing Power and Operation.
Turn off any nearby equipment that emits infrared energy, such as a radiant room heater.
Make sure there are no objects between the remote control and the IR receiver.