HP Officejet Pro K550 Printer - Manual (Page 71)

Light description/Light pattern Explanation and recommended action
Link light is off. Activity light is off. The printer is turned off or is not connected to the network.
▲ If the printer is turned off, turn on the printer. If the
printer is turned on and a network cable is connected,
see
Problems connecting to a network .
ENWW Interpreting network connector lights 63