Hello. My name is Michael. I can help you with your question if you still need assistance.
The first thing I would check here is that the incline motor is actually working. To do that, open it up and without power plugged in, apply 12-18v dc directly to the incline motor. It should move based on the polarity of the voltage. If it does, then the motor itself is working. After that, check the voltage coming INTO the motor when you operate the controls. If that does NOT vary when you operate the incline controls, then the problem is very likely the motor controller board - this is the most common replacement on these machines. You can also make sure that the signal is coming from the controls themselves, but for them not to be would be a far less common issue.