21:10 error When I turn on the plotter, it runs through it's start up routine and stops with a system error 21:10 Any ideas?

Hi HotRoddy,

This is a Service station error. Check for obstructions in the service station on the right.
Turn on the printer in service mode by holding down the UP arrow and ENTER keys (simultaniously).
Enter Service Utilities, choose Unlock Carriage. Turn the printer off and move the carriage to
the center of the printer. Turn the printer back on. The carriage and service station should
return to their home positions.
If the error returns on power-on, the service station will probably need to be replaced.
Parts and diagrams can be found at partsurfer.hp.com.

Hope this post was usefull for you.

Thanks,
Robosoft.