Sorry to hear you are having these issues with your treadmill, usually when this issue arises it is a very good sign that your Motor Control Board has short circuited and needs replaced.
The best test to perform if you can
is swap out the board of a machine you know to be good; Into the machine that is running at top speed at start up.
If you can not perform that test, unplug your machine and remove the main shroud. You want to disconnect all wires from the board, keeping track of where each connection goes. inspect the board for any visual damage, along with the cables for any crimping or damage to them.
Reattach all wires to the board, and plug machine back in without reattaching the main shroud. This way you can also check the board while the main shroud is off, you want to check that the LEDS are on.
Assuming none of the above works, it would definitely be your motor control board that is the issue and needs to be replaced.
If any other questions please feel free to contact our Technical Support Team at 888-713-2880 or check out our Tech Support Center at www.sportsmith.net
we would be happy to help you