Schematics for a horizon ct81 control board

Thread Starter


Joined May 16, 2019
So my treadmill will not run, everything else works, so I think it is the control board. Does anyone's have access to the board schematics?
Thank you


Joined Dec 10, 2019
hi ,

i need schematics too. i have same problem and replace all caps, mosfet, kikback diode, zener diode,.

thank you have a nice day!


Joined Dec 10, 2019
Don't recognize that one.
Have you tested the motor?
yes motor spin with my battery pack from 12 v cordless drill, replace mosfet irpf260n, kikback diode, all caps, u4 (un136 chip) u5 (tlp521 chip) u3 ( uc3842 chip) big relay , and 2 zener diode. and still have same trouble. treadmill work for up down, display work. i check speed sensor and belt sensor and test ok.

this reason need schematics


Joined Dec 10, 2019

i have treadmill with control board problem on horizon fitness ct 81 board is JDYF02L. replace all capacitors, zener diode. u3 (uc3842b) u4 (6n136) u5 ) (tlp521) q4 ( irfp260n mosfet) ) d4 ( 30ua60 kickback diode)
i have same problem speed motor not work but display and up and down motor work, no error message.
i need schematics or infos for troubleshoot this board

thanks you have a nice day !!


Hi, were you gents able to diagnose and repair your MCB's? I have a CT7.1 with a similar issue. Belt started stopping intermittently while running, I would cycle the power and unit would start top unit asks for speed but MCB will not output to motor. Any help would be appreciated...especially in this Covid isolation... :p
20190615_103157.jpges el esquema de arnés para placas de 8 hilos de Jhonson fitness espero te sirva

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Joined Aug 21, 2008
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