I could not turn on the 2160 with my remote --- I had to use the main buttons on the 2160 to turn it on --- I changed the batteries in the remote -- it seem to start to work but the vol + - buttons worked some of the time -- I even held the remote a few inches from the front panel and the volume did not move all the time. Is there a way to figure out what is wrong -- also where on the front panel is the sensor for the remote -- thanks