HP 1055CMHP - Manual (Page 76)

Service Tests and Utilities
4-2
HP DesignJets 1050C and 1055CM Printers Service Manual
Introduction
This chapter explains how to use the built-in Service Tests and
Service Utilities and what to do if any of the Service Tests fail. If
possible, always perform a Service Test on the component that you
are about to replace, just to make sure that is the component that has
failed. If the test on that component passes, there is no need to
replace it.
Diagnostics - Self Test
Initialization Sequences
Whenever the Printer is switched ON, it automatically performs a
series of internal self tests and mechanical initialization sequences.
If any of the parts fail, a system error will appear and you should
consult Chapter 2 - System Error Codes.