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.
Try to tight the keypanel flexible cable vs Display Board and then tight the connector from display board vs Main controller board(lower board) and will be a good idea spray with contact cleaner the keypanel with carefully and patience.
Finally you will have 2 options if the problem persist: 1) display board faulty or 2) main controller board faulty. See. the block diagram how the main controller board has 90% of function in any treadmills.