Well we all know that there is no way of detecting if our remote (for TV, DVD Player, etc.) is working or not. Main reason for this is that we CANNOT see IR. IR, or infra-red, is basically light beyond the red (and yes that is red and not dead!) wavelength, which we cannot see. However, for this reason, a lot of devices use them to communicate. So when you press a button on your remote, it emits a light of the IR type, which carries a command, for example, turn the volume up, change the channel, power off, etc., and when the receiver sees this command come through, it performs that function.
Anyway, so we cannot see IR. This means that when we press the button on the remote, we do not see anything happening, and have to wait for something to happen on the receiver, such as the TV or other device. Certain manufacturers will sometimes put a visible LED on the remote as well, such as remotes from SKY or Virgin, however these visible LEDs once again do not represent the IR coming out.
However, most of us, carry in our pockets, devices that will SEE infra-red. Most mobiles have a camera in them, and normally most of them can see IR. In fact, you can see it on the preview / view-pane without even taking a picture. The video above shows me recording what I saw coming out of one of the remotes I have, with a Samsung Galaxy S.
So yeah, if your remote doesn’t seem to be working, change the batteries, or actually test whether it is emitting anything or not. Cool party trick for all your geeks out there. Sad reality for anyone who has to perform troubleshooting.