Quite possible something blew on the controller board. I had a short in my 12v power with a too large a fuse & it cooked the control board on my EQM35 (basically the same board) - I don't use a handset but if I plug one in it can't connect to either motor. But I'm not savvy enough with electronics to know what's wrong or what to do about it.
If you get it figured out maybe I can send you mine to have a go at - got to be cheaper than a replacement...
Good luck with it,
Mark