Papillon,
The cm20 use's a 4pin plug,black,red,green and yellow. I'm assuming that it is the plug,But it could also be the control itself. I have three of them that I used for many years with no problems. You might want to give Mrc a call at their customer service at (732) 225-6360 And see if they can help.
Good luck,
Frank
I had a similar problem a week ago . I used a long coiled spring telephone handset cord. The plug is a 4 pin wide style but the jack in the controller handset is 6 pin s wide the 2 outside pin positions are not used.I think what happens is as you stretch the cord over time the 4 pin plug twists and distorts the pins in the controller handset.Look inside to see if the pins are twisted or out of their slot or are crushed down in their slots. If they are use a paper clip with end of form into a small hook you can use this as a tool to straighten them out .I used an old spring hook tool saved from my days as a teletype serviceman. My experience as a telephone man made me check that jack in the Handheld controller .
The original CM 20 cord most likely came with a 6 pin wide plug which would not twist . I bought both of my CM 20s used. 6 pin plugs are available .6 pin flat cables or round not coiled are available .I don`t know about coiled 6 pin cords.
Hi,
I had two on my last layout and they performed error free for many years. Yours definitely sounds like a "non user fixable" situation, and I would call MRC and talk to them of returning it for service.
Forgive me for asking.......... is it possible someone disconnected wires and reconnected to the wrong terminals?
Mobilman44
ENJOY !
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
For many years now I had no problems with the MRC Control Master 20 I currently use as the main control on my DC layout. Yesterday, aft a few days without it, I encountered this problem: when I put the control On, the loco on the open block started full speed even if the speed knob was at 0. I made some test to determine if it was the control or the loco. I found that whichever loco I use the problem is the same.
When the control is in FORWARD the loco will start forward at full speed when I put the transformer On, even if the speed knob is set at 0.
When the control is on REVERSE, the loco will crawl FORWARD but only when the speed knob is set at maximum.
Did someone ever experienced that problem? Is there any easy fix for it or do I have to consider buying a new control?
Guy
Modeling CNR in the 50's