I have the following:
Proficient Infrared Systems repeater
Infrared Resources 7ft Visible IR Emitter Cable
Motorola DCX3400 cable box (Time Warner Cable)
Polaroid HD LCD TV/DVD Combo

First of all, I am a beginner, so please keep the responses a simple as possible or explain them well. The problem I'm having is that my repeater does not seem to be able to change the channels on my cable box. The IR receiver is on my LCD TV in another room and the IR emitter is located on the cable box where i should be able to recieve a signal. When the system was professionally installed, it worked perfectly.

About 3 months ago, I noticed that I was not able to get a signal all the time. I would move the wires in the cabinet containing the cable box and it would work again. After a while it would not work at all as if the repeater had no power. Just recently, I changed the power supply adapter to one I had around the house and the repeater suddenly seemed to have power. I was still not able to get a signal so I exchanged my cable box for the one mentioned above. I am now able to get a signal that shows my cable programming on the LCD but I'm unable to change the channel unless doing so on the cable box front panel. I then ordered a new IR emitter from Infrared Resources mentioned above, in case my emitter that came with the Proficient system had been fried.

So, everything seems to be in place, but I'm still not able to change channels in the other room. I am using the cable box's remote. When using the remote, the IR receiver (in the room with the tv) and the IR emmiter (in the entertainment cabinet) both blink as I push the buttons.

I need to know if there is something else I need to do, like entering a code into the remote or cable box to get everything to function properly. Please help! I am not able to locate the AV professional who did the previous install.