98 Disco radio issue (not Code)

Hello all! I purchased a 98 Discovery about a year ago. It has it's querks, as I'm sure they all do, but I love it. I am having a slight problem with the radio that began a couple months back. I have the code, so that is not the issue. For some reason, I am only getting sound out of the rearmost speaker, and at a greatly reduced volume (it can only be heard when the engine is off). I have checked the balance and fade settings. I also checked the wiring and it seems ok, and the fuse on the back of the stock radio looks intact. Its very strange, as the sound began going out intermittently, and is now gone altogether, except as I mentioned above... Kinda frustrating as it isn't much fun driving in silence, and playing music over my phone isn't much of a substitute! Has anyone heard of this issue before or have any ideas what it might be? I'm considering just replacing the stereo with a cheap aftermarket deck but not really sure that's gonna resolve the problem! I'd be grateful for any thoughts or ideas!

You have gone deaf. Consult an ENT specialist.

touche... shoulda seen that one coming!