Janome New Home MC8000 Buttons Not Working?

I had a technician replace my backlit display and it now works! We have calibrated the screen (possibly also called a shock reboot from some notes I've read on this forum) by pushing the needle up/down, reverse, and start buttons while turning on the machine. But now these buttons don't work at all. I can sew and use all my stitches fine, but cannot reverse, use my start button, or set my needle to the down position. My user manual does not address any problems with these buttons and I have not found anything online regarding such issues. Ideas?