My 2008 Gravely z52 worked fine this morning, i took a break and when i tried to start again it just sorta "buzzed". The engine doesn't turn over, i can hear all of the safety "clicks" as i re-check the mower switch and the control arm positions. When everything is set, when i turn the key, i hear a soft "buzzing" coming from under the seat, left side. Any ideas on what might be the problem? This thing has 92 hours on it so it is virtually brand new.