My 2000, Scotts 1742 lawn tractor won't start. Turn the switch, nothing. This is the second time around. That was the story a couple weeks ago. Battery had a bad cell. Replaced battery, rapid ticking sound on turning the key. Went to JD dealership, picked up a new solenoid, replaced it, and my mower started right up. Mowed the lawn, put the tractor away. Went to mow the lawn yesterday, nothing. New battery, new solenoid, one mowing and now I'm back to a silent, immobile lawn tractor and a rapidly growing lawn. Any thoughts?