Vector 1950 no screen display but the unit still running

I have a problem with Vector 1950 it doesn't have a screen display but still running. Possible a faulty mirco relay board? I checked on the stop start toggle switch there is a 12volts power, checked the harness end to end there's a continuity I have used as another screen display midule but still doing the same. I am suspecting a faulty micro. Please need a help to fix it.

So the ribbon cable checks out?