iva c801 brain problem

I just recently installed a pair on headrest monitors. Everything was working fine, but yesterday the nav and aux 2 input stopped functioning. The slim PS 2 is connected to the Aux 2 input via rca's, so that is the only connection. The nav is conneted via the adapter, and the fuses(5 A) are both fine. The head unit is not displaying either the nav or aux 2 on the source menu screen. So could it be the brain or a short circuit somewhere? If so, then replacing the brain might be cheaper than the whole unit itself.2001 Corolla S and 2005 Neon SRT 4 ACR.

Well, I was looking online and found an auction for a new brain for the head unit. So hopefully I can purchase it to replace the current one. I will recheck all the connections before installing the new brain....2001 Corolla S and 2005 Neon SRT 4 ACR.