I am trying to do a little home repair on an older set of CH Pro Rudder Pedals. These are a 3-axis USB game controller, and I have isolated the problem to one of the potentiometers in the right break axis.

The signal from the pot initially had a large amount of hysteresis when read by the controller card. It took about 70 seconds from the reading to fall from 255 to 6 when the access was moved from one extreme to the other. I could prove it was not the card or software by switching the left and right axis pots an observing that the problem migrated from one side to the other.

The potentiometers in question are a bit interesting. They all run 120KΩ, but while the armature rotates the typical 270° the active range is only over the middle 90° of movement; beyond that the pot reads full deflection. The malfunctioning pot reads open circuit on the center tap and the expected 120KΩ from end to end on a multimeter. It has a 1/4" shaft with a 3/8" deep half cut on the shaft. The two good ones are marked HP-100A 0004 ROC the bad one is stamped 900-604B 0105.

My preference would be to simply purchase a replacement potentiometer but I've never had to find one this specific. The narrow active band seems particularly unusual. Some CH Products forums suggested that this is a custom made part and that they cannot be purchased new any longer.

If I cannot get my hands on a replacement, I wonder if I can fix the old one. If I remember pots are among the more straightforward devices. Can I open this thing up and fix what ever is wrong with it?

  • \$\begingroup\$ you can certainly try to repair it \$\endgroup\$ – jsotola Aug 23 '19 at 6:40
  • 2
    \$\begingroup\$ Photos would help. If you can find a mechanically similar pot, you might be able to replace the spindle and wiper - there's one or more metallic contacts that run on the resistive track that may have worn or relaxed to the point that it isn't making contact any more, but if the wiper has worn away the track you won't be able to recover the part. \$\endgroup\$ – Phil G Aug 23 '19 at 13:22

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