HP DesignJet Z2100

System Error Codes
2-10 Designjet Z Series — Service Manual
 Switch the Power OFF from the back of the Printer and disconnect the
Power cord. Reconnect the power cord and power On the Printer.
 Check that the Trailing Cable is not damaged.
 Check that the Trailing Cable is correctly connected betwen the Main
PCA and Carriage PCA and make sure that the connectors in these
boards are not damaged.
 If the System Error continues, replace the Trailing Cable  Page 6-92.
 If the System Error continues, replace the Main PCA  Page 6-163.
 If the System Error continues, replace the Carriage PCA  Page 6-138.
System Error: 21:YZ
Problem
Description:
Fail moving Service Station.
Corrective Action: Try the following:

 Remove the Right Cover and make sure the cables from the Printmech
PCA to the Service Station are connected and are not damaged.
 Make sure that the Service Station path is clear. Remove any visible
obstacles (e.g. screws, plastic parts, etc...) restricting the movement of the
Service Station.
 Perform the Service Station diagnostic test to troubleshoot the problem
further 
Page 3-45.
 If the System Error continues, replace the Service Station  Page 6-60.
 If the System Error continues, replace the PrintMech PCA  Page 6-71.
System Error: 21.1:YZ
Problem
Description:
Fail moving the Primer Motor of the Service Station.
Corrective Action: Try the following:
 Remove the Right Cover and make sure the cables from the Printmech
PCA to the Service Station are connected and are not damaged.
 Perform the Service Station diagnostic test to troubleshoot the problem
further 
Page 3-45.
 If the System Error continues, replace the Service Station  Page 6-60.
 If the System Error continues, replace the PrintMech PCA  Page 6-71.