HP LaserJet 4050 Printer series - Manual (Page 36)

14 Chapter 1: Printer Basics
EN
Using the Printer Online Help System
This printer features an online help system on the control panel that
provides instructions for resolving most printer errors. Certain
control panel error messages alternate with instructions on
accessing the online help system.
Whenever a [?] appears in an error message, or a message
alternates with FOR HELP PRESS THE ? KEY , press the [Item] key
to navigate through a sequence of instructions.
Note To exit the online help system, press [Go] .