HP Color LaserJet 4730 Multifunction Printer series - Manual (Page 245)

5. Align the print cartridge with the tracks inside the MFP and insert the cartridge until it is completely
seated.
NOTE If a cartridge is in the wrong slot, the control panel will display the message
INCORRECT <COLOR> CARTRIDGE.
6. Close the transfer unit.
ENWW Managing print cartridges 225