One of my Intermountain F7's had an apparent decoder malfunction and would only run full throttle either direction. I replaced the offending decoder last night. Now the F7 only runs very slowly. It will not respond to re-sets of CV2,6,5. No matter what I set the speed doesn't change. This F7 runs at half the speed of it's sister F7.
My question, is this a loco mechanism problem, or an internal problem in the F7, or a second bad decoder problem? Or should I send the offending loco back to Intermountain? When purchased these two ran together, speed matched wonderfully?????
Please help,
Doc