I was feeling great after fashioning and resoldering 3 broken contacts on an N-Scale MRC 1952 sound decoder. Having also torn the host Kato GG1 down for brush replacement and gotten it back together with no leftover parts, things looked promising. With Kapt toon tape painstakingly burnished on the outer sides of the motor contacts and opposing surfaces of the inner frame halves, the decoder slipped nicely in place. I taped down both ends of the decoder to hold it firmly in place and set the loco on the test track. I turned on my Zephyr, tapped LOCO punched in the address and tapped LOCO again. The speaker started pumping out the hum of the GG1 traction motors and when I tapped "0", the front light came on. Flipped the direction to reverse and the the headlights swapped ends. That isn't the end of the story, but it is the end of the good part - so far. The loco does not respond to throttling up in either direction. Ok, we know that the decoder is fine but power is not getting to the motor. I tested the motor after replacing the brushes, so I know that the problem is somewhere between the decoder output and the motor input. Further testing revealed that pressing down on both sides of the decoder right above the point where the motor contacts are soldered to the circuit board makes the locomotive spring to life. Since one of the decoder repairs I did was to fashion and solder on a replacement motor contact, I'm m guessing cold solder joint, I won't know until I pull out the decoder and check it all out. To be continued. Don
I know how you feel. At least it sounds like you didn't burn the decoder. I just literally had a look at a decoder today, and lost one of the motor contacts. About one hour later, it's working again.
I am not sure how the Kato GG1 is setup inside but if it is like many many other Kato locos the motor wires are flat copper/brass tabs that fold over the decoder and are held in with a small plastic clip. This area is problematic and can be cured usually 2 different ways. I prefer to take the metal tabs and bend them down a bit near the ends then clip them into the little plastic clip. This provides a bit more downward force on the motor tabs to the decoder. I have not had any issues since I started doing this and if you ever need to remove the decoder it's not an issue. The second method which you will see online quite a bit is soldering the motor tabs to the decoder. This works great but makes life a bit more difficult if you ever need to remove the decoder or motor. Now if the decoder the type that has the tabs that straddle the motor and touch the brush pockets I found sometimes just pushing them inwards a little helps. Sometimes even a piece of masking tape inside the loco shell to apply a bit more pressure to the brushes.
