Treadmill Problem

Discussion in 'General Electronics Chat' started by jscolly, Feb 3, 2018.

  1. jscolly

    Thread Starter New Member

    Dec 3, 2017
    1
    0
    Hi, I have a Reebok 11300 with a similar problem. Checked the motor with Automotive Battery and it ran OK. Found blown Mosfet on Control Board and replaced but immediately blew fuse. Examined motor commutator and there was a burn [like tiny weld splatter] on one segment. My question is if I bypass the faulty segment will the motor be useable, there are a lot of segments so maybe any ‘imbalance’ will be negligible!?
     
  2. scrumpydc

    Member

    Jan 23, 2018
    48
    5
    i turned my one of these into a belt grinder do you have any photos of the weld splatter
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
    15,675
    4,562
    Replace the blown items and test with a suitable 100w lamp first, It is possible the com is still OK, you could try and clean the com up first, easiest if the armature is removed from the motor first, if doing this, take care not to damage the magnets when withdrawing the armature.
    Max.
     
  4. IamJatinah

    Member

    Oct 22, 2014
    112
    22
    If this is an Icon control board, say something like the MC2100 series there is a known zener that fails as well as the possible FET shorting, and kickback diode to check, then the small drive circuit between the programmed CPU / PWM generator IC on the control board and that main FET switch needs to be verified/checked. I have also seen the SCR circuits fail on these, controlled with an opto to the gate and a 511ohm resistor seems to stick in my head for some reason. If the resistor is fried, that opto and/or SCR circuit should be checked. Parts to check for the MC2100....
    FET - Q2 - IRFP250 (replace with IRFP260N)
    Kickback - D13 - 30A600v ultra-fast
    Predriver for FET - U5 - can short killing FET drive
    SCR - Q1 - Teccor part maybe
    Opto driving that SCR - U4 - using R17, D9, C12 "gate-side"
    Also check D7, D8 and Q5 that should enable control side of SCR opto U4
    Good Luck!
     
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