UIRT2B problem with transmitting

Sorry to ask the question here, but I'm running out of solutions.
I have a UIRT2B that I bought about 3 years ago that up til now I have not used as an emitter. I'm trying to set it up to control a DVD jukebox for Christmas and I cannot get the emitter to send a signal. I found a post here that mentioned using a pair of headphones to hear if the transmitter is working properly. When I did that the right channel sounded fine, but the left headphone did not make any tones and became hot within a few minutes.
I verified the my wires with a meter, and the wiring matches that shown on this site: http://www.fukushima.us/UIRT2/UIRT2B-External%20Connections.htm
I want to stick with this UIRT because I have it installed inside my HTPC instead of having a separate block sitting on top.
I would appreciate any help you guys can provide.
I have a UIRT2B that I bought about 3 years ago that up til now I have not used as an emitter. I'm trying to set it up to control a DVD jukebox for Christmas and I cannot get the emitter to send a signal. I found a post here that mentioned using a pair of headphones to hear if the transmitter is working properly. When I did that the right channel sounded fine, but the left headphone did not make any tones and became hot within a few minutes.
I verified the my wires with a meter, and the wiring matches that shown on this site: http://www.fukushima.us/UIRT2/UIRT2B-External%20Connections.htm
I want to stick with this UIRT because I have it installed inside my HTPC instead of having a separate block sitting on top.
I would appreciate any help you guys can provide.