If the console takesbatteries, replace them. If this does not work or your console does not requirebatteries, check the reed switch or optic sensor.
Reed Switch:Unplug the treadmill and remove the motor hood cover. The reed switch is mountedon the frame next to the front roller pulley. There is a magnet glued into thefront roller pulley. When adjusting the reed switch, make sure it is pointingdirectly at the magnet. Move the tip of the reed switch within 1/8" of themagnet. Also, check to see that the wire is not damaged, and is connected tothe console.
2nd Step: tight the keypanel vs Display board and clean with contact cleaner spray . Tight the connector from Display Board vs Main Motor Board. See the block diagram how the main motor board has aprox 90% functions in any treadmill. Good luck, Now you will strong resultant in determine what is faulty.