Sounds like a track signal issue. It could simply be out of tune, that happens to the old TMCC BASE1 as it has a coil to determine the frequency. It could also be the signal is simply not there, the only way to know is to measure the signal. Here's a rig that the late Dale M. came up with, you could compare your base to his and see if you have a big difference. This is done with the base not connected to anything. Since yours works, if he has a similar reading, I'd think the base is out of tune.
