HP Color LaserJet 8550 Multifunction Printer series - Manual (Page 176)

EN Printer Response Problems 175
Color toner carousel will
not rotate The power cord is not firmly plugged into both the
printer and the power receptacle. Remove and
reconnect the power cord. The printer must be turned
on.
Verify the clear door is closed, the imaging drum and
black toner cartridge are installed (including removing
the orange seal from the black toner cartridge and
swinging the upper lever to the left), and the upper right
door is closed.
The printer is on, but not
receiving data (Data light
does not blink and
nothing prints) READY is not displayed on the printer control panel.
Press G O to bring the printer online.
The printer has lost communication with the network.
Turn the printer off and then turn the printer on to
re-establish the connection.
The network cable is not correct for the network
operating system. Select the correct network cable for
the network operating system. For more information,
see the getting started guide.
Problem Cause and Solution