HP 1055CMHP - Manual (Page 134)

Service Calibrations
5-18
HP DesignJets 1050C and 1055CM Printers Service Manual
the front panel:
In this case, to resolve the problem, try the following:
1 If the calibration pattern is bad:
n Try recovering the Printheads using the front-panel menu and try
the calibration again.
n If the calibration pattern is bad again, then replace the Printhead
of the color that is bad.
2 Perform the Electronics System test
⇒
Page 4-5.
Press ENTER to continue
Calibration error.