Horizon CST4.5 Motor Control Board

I would give this 4.5 stars if that were an option. I wouldn't normally mention the supplier in a product review but I think it's relevant for this particular part.The Good:I bought this for my CST4 and it was a direct replacement for the most part (see below).The seller included treadmill lube with the new controller, that's a nice touch incase you don't have any.I paid for expedited delivery and it was delivered quickly.The part looks well made and has all the correct connections.The Not Terrible But Worth Noting:The bottom plate of the replacement is slightly thicker than the original making the original screws almost too short. I had some longer screws handy and replaced the originals. I'm not sure with vibration if I would have trusted the short and tapered original screws.While all the correct connections are on the new board, some are in a slightly different position that required cutting the zip ties, moving the wire and re-zip tying.Additional Step Required:After installing the new controller, my treadmill speed was considerably off. At 2 mph on the screen, the belt was running closer to 10 mph. I found a video online for the Horizon speed calibration procedure and it worked.If the box with the part had two new, slightly longer screws, three or four zip ties and some information about recalibration, this is a great replacement. As is, it's still really good.One Other Piece of Info:My treadmill had a slight motor vibration just before the controller went bad. It was still present after replacing the controller. I noticed that the toothed wheel on the back side of the motor responsible for reading speed had some thick dust build up in a few spots. I cleaned that dust off (with the treadmill unplugged, don't mess around here) and the vibration went away. If you're replacing a controller, you might want to inspect this part.That's it. I'd buy this part again if it went bad a few years from now.