I've got a 52" Toro Proline (30761) - I pulled it out last night to mow, got two swipes done, then the blades disengaged, like I had let off the safety lever. Now it won't engage at all. It's electric PTO, and there's a safety lever on the T-bar handle. So, I'm guessing that either that switch went bad, or the electric PTO switch went bad, or there's something screwy with the clutch. Is there a way I can find out for sure what the culprit is before I go buy a bunch of parts? Thanks a bunch!