kenwood kvt 717dvd

Hey guys

Im new to this forum and I would like to introduce myself. My name is Chris and located in Regina, Saskatchewan. Incase you are wondering, its in Canada lol. I have been installing stereos as a hobby for 3 years and never had any problems so far. I have a Kenwood KVT-717DVD unit in my car and its been in there for about 2 years. A week ago it was working fine until the next morning it quit working. The screen powers on and folds out but I just get a message saying that "Data cable cannot be found". I checked the cable from the head until to the brain and nothing had gone loose. The brain is mounted in the Trunk right beside the amp. I first thought that this could be a ground problem so I checked my ground connection and it was good. I can hear the fan running in the brain. The data cable is sending power to the unit. When I disconnect the Data cable the fan does not run. But when I disconnect the power for the brain while the data cable is still plug the fan stays running. I am thinking that  there is power problem with the brain.  This one has got me thinking.