Electrical Questions? Ask an Electrician Online.
Hello, my name is ***** ***** id love to try to help.
Id check the load side connections on the D4200 (if you could give me more info on make and model of the unit it would be helpful to me)
if not load side on the unit, you may have lost something in a j box or fixture, as in a neutral termination was lost ect
id assume the unit is working if lit up and showing power feed to lights, but if i can get the make and model we can dig a little more.