No Signal from Positive Pole on FL Speaker output on NR1608

I noticed that my FL speaker was out. If I plug the FL speaker into the center channel and play the pink noise test tone in the Marantz setup on center channel I get sound out of the speaker so I know there are no wire continuity issues and the speaker works. If I connect the center speaker to the FL and play the test tone on the front left I get nothing as well. If I connect the negative pole of the speaker to the FL negative and Center positive and play the center test tone I get sound on the speaker so I know the negative pole of FL has continuity. If I connect the speaker negative to the negative pole of center and positive to FL positive pole and play the FL test tone I get nothing. I am not able to send the AVR to an authorized repair facility so I would either need to diagnose this myself or find a local repair shop. Is this kind of thing a common capacitor issue? Are there specific things I should look for? I have yet to open the AVR up, but thought I would post here first.