IR or infrared light is normally not visible to the human eye. However IR signals can be visible through a digital camera viewfinder. You can use the viewfinder of a mobile digital camera, too. However some cameras seem to block IR range and IR may not be visible.
Problems with IR remote control or other IR interfaces like mobiles, laptops or printers with IR can be very difficult to diagnose.
- First check the basics. If it's a battery-operated device, ensure that the batteries are fully charged.
- Check the contacts of the battery. Remove any rust or particles on the battery contacts.
- Turn on and point your camera to the IR emission area, usually identified by a dark red plastic area.
- Press any button on the remote. If the IR device is a mobile, try sending a business card via IR.
- If the IR device is working, you'll find the light being emitted from the IR LED, usually with a blue tinge.
If the IR interface is not working, you'll not find any light being emitted. You can check any button on the remote by pressing the button and watching it on the camera.