IR remote controls use infrared light to control TVs, DVD players and other electronic devices. When an infrared remote control is not working, or is working intermittently, the cause might be interference.
Ambient light, especially sunlight, can overload or desensitize the sensor on the electronic device and cause it to miss signals sent from the remote control. Devices that use infrared to communicate with the remote control should be shielded from bright, direct light.
If you use several infrared remote controls at once, they can interfere with each other by scrambling the IR codes that are being sent to the device. Separate your infrared receiving devices to avoid this interference.
Fluorescent Lamps with Electronic Ballasts
Electronic ballasts regulate power supplies in newer fluorescent lamps and bulbs. These ballasts can modulate high frequency light coming from the lamp or bulb and confuse the receiving device.