Like tileplow says, check voltage to clutch by unplugging it and checking with a test light or multimeter. Remember all safety switches must be closed for the blades to turn on so someone will have to sit in the seat with enging running.

I have had a couple of the push-pull switches go bad (the one that turns the mower on). One I had I could pull it out and the mower would not go but could twist the knob a little side to side and it would go, indicating the contact points inside were bad. Had a tractor do that.

A possibility is some safety switch bad but I suspect the mower would not even start if that were a problem. Seat safety switches are notorious for going out but likely it would also not start if that was the problem. On my Bad Boy it also has a safety switch on the parking brake. One on each hydro controll lever. Any one of them not working will not start. Not sure about which ones are involved with blade engagement. Usually just kills the engine if doing something not approved by the safety switches.