I have a Stromer display that stopped working, but it turned out it was the battery in the display. After replacing the battery in the display it powers on but I only get a "NO_BATT" flashing message no matter what I do. I know for sure the battery(ies) are charged fully, and the headlight/taillight work so I'm not sure what the issue is. I did test for voltage and I'm getting 40V on both batteries. I don't have the wiring diagram, and do not know what signal wires to check. Does anybody have any suggestions? Do these displays go bad?