Audio went to one channel outta nowhere.

I changed nothing and now I cannot get stereo audio to come OUT of the Behringer. it worked fine for a month, both channels, but one day went to work on a track and the audio is coming out of one channel, I changed nothing. What could be the problem?

Here are some pics of the setup.

It might be broke

I think its the behringer, ive checked every cable with another source and they are fine. this is the second behringer im on now.

I have a Behringer and it sucks.

I graduated from Arlington in 2001 man, nice to see a local on here. Now I live over in Garland.