What breaker is tripping?
Did you take the unit apart to move it?
OK I would Check the wire that goes through the arm it may have been pinched or damaged causing a short
Next would be to unplug the red and Black wires from big drive Motor. Then turn unit on and see if there is any change
Next would be to replace that breaker itself.
If still after all that you have no change it sounds like the new board you put in is bad
You may be able to find at a local electrical store, I'm not sure. We always just order our Parts Direct from company. You can also try fitnessrepairparts. Com or Treadmill doctor. Com
OK do you have the safety key in place?
Next trace that wire up the arm to console make sure it's plugged into the console
Well I would try swapping boards, next would be to use a volt meter to test continuity from the data cable. Unplug from console and lower board. Then test each prong to make sure the data cable is OK
I would just change it out, I don't think there is any way to test. They just wear out over time