John Deere L110 Won't Start

Hoping that someone can give me some hints on what to look for with my lawn mower. I have a John Deere L110 which is about 12 years old. The mower has a 17.5 hp Kohler engine and was running fine until the other day when the mowing deck belt broke. I pulled the mower into my shop, put on a new belt and when I went to start it the starter wouldn't turn over. All I hear is a clicking sound from the solenoid when I turn the key. I have had the battery checked and it is good. I have also made sure I can turn the engine by hand. The problem doesn't make sense and I can't figure out if the problem is due to the belt breaking or is just coincidental. Could the starter have gone out or been effected by the belt breaking? I have tried to jump the starter directly from the battery and it does nothing. I suppose that means the starter is dead. Right?

Start by pulling the plug and see if it will spin with the starter like that.
If not try to turn then engine by hand.
Make sure that the spark plug is well out of the way because if the cylinder is full of fuel and it is nice & warm as the fuel is squirting out of the plug hole, singed eyebrows time.

Thanks for the hints. I started narrowing down my issue and discovered the starter was bad. I figured I didn't have anything to lose so I opened up the starter and saw where the "magnet" (for lack of not knowing the proper name) had broken inside. Luckily, it broke just in one spot so I pulled out the pieces that were jamming up the starter, put it back together and it worked.