The Digitrax DZ125 decoder I ordered when I had managed to burn the DN144 sound decoder (as told in the previous post) has arrived and been installed. It was an easy install and everything went along fine. Even if SW (Cotton Belt) 7292 does not give off any sound, it at least runs. Here is a picture of #7292 sitting in the siding, being overtaken by SP 4810 and 4827.
SP 6702, on the other hand, is a poor sight, as you can see in the next picture.
It does not run very well at all, and never has. When started it barely moves at all. It creeps and jumps forward, with an occasional nudge. But after a while it sort of warms up and runs quite nicely. I have tried a bunch of things, cleaning, resoldering the decoder etc but nothing seems to help.
So when I bought a new docoder (DZ125) for SW 7292 I though I should get one for 6702 as well. Yesterday I took out the TCS M4 decoder and installed the DZ125 instead. But no difference. The loco behaves as before. I'm running out if ideas.