Error Codes

I am getting the Error Code "Instrument Error" "Calibration Error" (Low) I know this is an old machine and I have tried to call tech support but of course that does not seem to be in existence anymore. The model is a 5772. Any ideas? I have cleaned it, unplugged it, made sure everything was plugged in correctly but I still get the same error.  i should have said it is a Clinitek 100 Model 5772