I'm presuming you are using either 'All Channel' stereo or you have assigned the rear surround channels configured to run as zone '2' speakers? Obviously, this is a surround channel AVR, not a stereo amplifier. so that may be the cause of your issue? Unless you are running in 'All Channel' stereo mode or using a zone '2' setup, that would certainly explain why you are not getting sound from 2 of your channels, as your AVR is using the other speakers as surround channels. Plus, if you have set the AVR up correctly, you may need to remove the speakers from the ceiling, to see if they are connected correctly, and there are no loose wires or incorrectly connected wires (as in, L/R cables are connected correctly). I'm sure others will be able to give you some advice as well. Good luck.