Last year when I was first putting together my control box I assembled my PMDX-126, PMDX-107, and PMDX-134 as described in the documentation. However, one axis had no output. The other three worked fine. I wasn't sure if I had some how done something wrong. So I removed the 134 and wired the drivers to the 126 terminals. All worked well. About that time my medical issues distracted me from following up any further. When I started to revive my CNC router I decided to try the 134 again in hopes of reducing the amount of cabling inside the control box. It appears that the #3 axis has no output. I checked the ribbon cable and it appears good. I tried re-seating the 134 with the same results. Is there a way to test the ribbon connector on the 126 and/or the 134 to isolate the problem?