Are the mowing blades still engaged with a lever or switch?

You won't be able to start the engine if the blades are engaged.

There are different versions of your tractor- so the model # would be helpful. I'm unsure what correlation there would be between jamming the blades and a no crank issue. You would have deck engagement, clutch and seat safety switches. You have a fuse in the wire between the + solenoid terminal and the key switch. I should mention that solenoids fail often enough. You hadn't tipped the rider? I assume that no longer attempting to start means that it won't even crank when you turn the key. Can you turn the engine by hand- either by the pulley or top screen?

Hi, I have a MTD mower with the exact same problem as yours (I ran over something, now it won't even crank). May I ask what the culprit was and/or how you fixed it?

Please help!