HP Color LaserJet 4500 - Page 42

36 Chapter 1 Troubleshooting control panel messages
EN
A critical EIO failure has occurred. X indicates the slot number of the
device and xxxx indicates the error type.
1 Turn the printer off and on to reset the printer.
2 Reseat the EIO card.
3 Replace the EIO card.
80 Service (xxxx) EIO error