I have one loco (N scale Kato F7 with Digitrax decoder) that has inconsistent operation. I have other locos identical to it with no problems. On some days, it will run with no problems for hours while other days, it will run about 10 minutes and then quit. Lights OK but no motor. Let it sit for 10 minutes then it will run OK again for an indeterminate period of time.
Initially I thought it was poor contact to the decoder so I soldered the connecion. Did not fix anything. My next thought was that the decoder is getting hot and shutting down. However, the decoder is not hot to the touch plus all my other locos set up same way have no such problem.
I still something is wrong with the decoder or the installation and I am thinking I should pull it out and swap in a new one to see if that fixes the problem. However, before I do that, I wanted to check with the forum to see if there was something I am overlooking. As an example, if the Kapton tape covering the pick up strip is not fully isolating the motor and allowing some current to pass directly to the motor, would that cause the loco to exhibit this problem? I know the Kapton tape is in a good position (I can easily see it) but I am wondering if the sharp edge of the pick up strip may have somehow created a small cut where the motor tabs pass by it and is allowing a small current leakage. If this is possible, I can pull the decoder and replace the Kapton tape
Paul D
N scale Washita and Santa Fe RailroadSouthern Oklahoma circa late 70's
You don't mention sound, so I'm guessing this is a lower-cost motion decoder. I would simply replace it, knowing that if you've got a contact issue the act of replacing the decoder will likely fix that, too.
It takes an iron man to play with a toy iron horse.
Clean wheels?
Robert
LINK to SNSR Blog
My guess is a defect in the kapton tape, wouldn't get better over time, a heat issue would. I don't know if a cold solder joint would act this way or not.
Dirty wheels don't get better by themselves either.
Henry
COB Potomac & Northern
Shenandoah Valley
Track and wheels clean. Other locos run fine. I think I will replace the decoder with a new one and replace the Kapton tape while I am there. If it runs OK, I will install the decoder in another loco and see if the problem shows up there.