Hi. I've have had a Sony STR-DE685 receiver for two years now. Just the other day the center channel and subwoofer went out for no apparent reason. No matter what component I use (DVD, CD, etc) there is still no sound. I connected the center speaker to one of the front channels and the speaker worked fine, so the problem seems to lie in the receiver. I made sure all connections were secure (speaker wire, input cables, etc), checked all the settings (powered subwoofer set to "yes", center speaker level set correctly) and the center speaker and subwoofer still do not respond. Even when I use the "Test Tone" function, the center speaker and sub woofer do not produce any sound. Any possible solutions are greatly appreciated.
It could be many things. A fuse running those two amps could be burnt out. Or maybe those two amps are shot. You can either take it to your local repair shop or look into purchasing a new receiver.
Sony usually has a 5 year warranty on their receivers. Is this the case with yours? I have a STR-DE835 that I just retired to the garage that is 6 years old. No problems throughout the life of that receiver, yet it was time to upgrade.