I have a John Deere GX75 Rear engine lawn mower. It has been a great mower over the past 15 years and I have maintained it thru the years. The other day will mowing, the engine died and would not restart. I thought it was the battery (the one in it was 4 years old) so I purchadsed a new one, but it did not resolve my problem. I get nothing when I turned the key. I checked the fuse and it is in good shape. Anyone have a suggestion?