Picked up a Kato SD80 N scale engine with said decoder. Loco did not run so I did a factory reset. The loco responds to the 03 address with lights only but will not run at all. Using a Zepher for the changes. Tried some different address and had same results, with only being able to turn lights on and off but no motion. No burn marks nor signs of a short. Bought the unit from a good dealer who said it worked fine before. Hate to send it back, any ideas out there Thanks
You may want to check the motor contacts to the decoder.
I agree with checking to make sure the motor contacts are touching the decoder motor tabs. I had the same problem with that decoder in an RS2. I also had to add some solder to the decoder tabs where they contact the frame. The board was too thin and was loose after installing. I also made a cheap decoder tester with a couple of old light boards so I could test the decoder before I went through the installation steps. While testing I can also program the new address into the decoder before installation.