Ok, the installation looks good. Do you have anyone with a Side Imaging unit on their boat that you could hook yours up to? Basically need to determine if its the unit or the transducer.
If not, I would get on the phone with Humminbird and see about getting it taken care of. I would send both the unit and the transducer. If you need it immediately, they will do advanced replacement if you pay for it, and then they will refund your unit when they recieve the damaged one.
Good Luck,
Robert