Temporarily, you can enter Service Mode -> System 2 -> Error Clear -> select "C-9903" -> Clear. However, if the root cause (bad RAM, firmware, cable) remains, the code will return, often within 24 hours.
If you are using a "Universal" driver, try switching to a model-specific PCL or PostScript driver. 3. Clear Internal Malfunction Settings (Service Mode) konica minolta code 9903
Follow this sequence from easiest/cheapest to most complex/expensive. Temporarily, you can enter Service Mode -> System