SIP speedo problem

[Tractorman]

The SIP speedo on the sidecar scooter suddenly lost the speedo and rev counter. The unit turns off and on ok and the clock, fuel warning and engine temp all work. I have checked the wiring connections and speedo cable and they are good. So I suppose it's the speedo unit or the power box. The speedo is coming on for 9 years old. Any one got any suggestion what may be the problem, please?