Some firmware versions require a CE Password to enter Service Mode. If the standard code fails, the machine may have a custom security lock.
Re-enter (Utility → Counter → Display Keypad → Stop 00 Stop 01). Navigate to System 2 . Select HDD . Select Installed (or Set) and press Install . Restart the machine one final time. Alternative: Partial Resets (Admin Mode) konica minolta bizhub c258 factory reset