I have a Troy Bilt Pony Lawn Mower that I have had about a year. It won't start. It will not turn over or make a sound. The battery is charged. The seat switch appears to be working properly. The mower is not engaged. It is not in reverse. I checked the fuse and it is OK. What else could it be?

Sounds like the connection to the starter is bad (corroded/loose) - or - one of the safety switches has not been tripped properly. e.g. My machine had a poorly aligned safety switch for the PTO lever... so it didn't get tripped and machine thought mower blades were engaged (non-start scenario) machine would not start because of this and all I had to do was re-align that switch so it would trip when PTO lever was in "up" position... and all was good again.
Hope this works for you.
Jumbo1114