Just for conversation, I fried a sensor once when i had the spark plug separated from the engine but still plugged into the cap. Turning on the ignition and rotating the engine without the plug being grounded to the engine turned out to be the wrong thing to do. That was on an old Sachs 4.2 with CH ignition.

Everytime I turned on the ignition after that the plug would fire once with the application of voltage, but nothing more. Repairs were definitely in order.