Right handle stopped working on Z4 #1. First occurance was when I had a long passenger train sitting in the passenger station drawing current from Z4 # 1 right handle. I drove a 2nd long passenger train onto that mainline (from a second mainline controled by a second Z4) and VOLT's dropped to zero).
I powered down the Z4. Let it sit for 30 mins. Powered back up and the second handle was working (Note: I had toggled off current to the siding holding the first passenger train... so just one passenger train).
Then toggled off current to both tracks/passenger trains... but left the Z4 powered on. 40 mins later I went to use and 2nd handle would not work. Again I powered down, waited 30 mins and powered up and it works.