It could be that you have a blown channel in your amp. Another possibility is that the input wire (not the speaker wire is bad. Try playing from a different source. Answer 2
Your amp dropped that channel.
Does anyone want to draw up a petition to end the sale of crappy HTIB's People pay $500.00 for them and they are basically crap. They sound so poor and they are so limiting.Answer 3
To be absolutely sure where the problem is, disconnect everything from the receiver except the FM antenna. With the receiver off, unplugged, and the volume turned all the way down, connect one speakers to the front left terminal, plug in and turn the receiver back on. Tune in an FM station, put the receiver sound mode into STEREO and slowly turn up the volume until you can hear the sound.
If that works OK leave the volume where it is, turn off, and unplug the receiver. Move the wire from the front left terminal on the receiver to the front right terminal and then plug in and turn the receiver back on. You should have sound. If not it is pretty safe to say that the channel is blown on the right side.
This problem is generally caused by shorting the speaker terminals when connecting speakers with the receiver power on. It is always safest to make all connections with the power off and with the receiver unplugged. If your receiver is still under warranty then it is "possible" they will repair it free of charge.