Help with Treadmill Motor Control board

Discussion in 'The Projects Forum' started by will_, Mar 26, 2012.

  1. will_

    Thread Starter New Member

    Mar 26, 2012
    Hi everyone,

    My treadmill has finally packed it in. It's a LifeSpan Ghia II 3hp model treadmill.

    The treadmill hadn't been used in roughly a year, when it was powered up again everything lit up and seemed ok until the Start button was pressed. Something must have short out, there was a burning smell and it tripped the main breaker in the house.

    Let me first just say I have a basic understanding of electronics but like to tinker with things and repair them myself if possible.

    Now the treadmill still turns on and lights up but there's no power to the motor. So far I've tested the motor itself with a cordless drill battery and it worked ok. Fuse tested and working. Control board has been taken out and from a visual inspection I can see some burnt/blown resistors. See pics






    Would this board even be repairable? Just to add, the treadmill was pretty filthy when I opened it up, looks like it was infested with rat faeces which is what might have caused all of this

    Any help appreciated. :)
  2. wmodavis

    Distinguished Member

    Oct 23, 2010
    Of course it is repairable!

    Replace all defective components including any that do not have the appearance of being "burnt/blown" but in fact are defective.

    Waa Laa! It works again as before.
  3. will_

    Thread Starter New Member

    Mar 26, 2012
    No joy.. I replaced 4 resistors, 1 capacitor and fixed up some tracks on the board

    resistors 10k, 150k, 6.8k, 390 ohm

    capacitor 104

    I must have made it worse because now the control panel doesn't even light up and it tripped one of the circuit breakers in the house :\

    Any ideas?
  4. BSomer


    Dec 28, 2011
    Did you at least clean that board?

    I would check the bridge rectifier, and the two other devices that attach to the heatsink. One of them may be an SCR which is another common failure point on those types of boards.
  5. will_

    Thread Starter New Member

    Mar 26, 2012

    Yes it has been cleaned, Just tested the Bridge Rectifier and I'm getting a .825 reading when probing both the AC1 and AC2, is this a sign of a bad BR?

    (+) (-)

    AC1 - = OL
    - AC1 = .487
    AC2 + = .484
    + AC2 = OL
    AC1 + = .480
    + AC1 = OL
    AC2 - = OL
    - AC2 = .480
    AC1 AC2 = .825
    AC2 AC1 = .825
  6. will_

    Thread Starter New Member

    Mar 26, 2012
    The two other devices that attach to the heatsink are a MOSFET Transistor and a Fast Recovery Rectifier Diode.

    Part numbers on them

    Transistor - G40NG0

    Diode - MUR1660

    I'm having a bit of trouble finding replacement parts, does anyone know suitable equivalent parts for these? I've been looking on here