Just got a new HP Designjet T770 hard disk printer, keep getting error code 21.1:03, turned power off and unplugged, still receiving same error code

what PC is this>? it is a PRINTER, so we say printer codes.
HP Designjet T770 Printer Series. front panel error messages (not told where you saw it and matters huge)

rule #1 is read the manual first for errors, we Control F search there.
HP makes finding manuals ******* the silly web site,IDKW
but do. and I use google to delve deep into HP, mighty guts.
is this your printer?
https://support.hp.com/us-en/product/hp-designjet-t770-printer-series/3980523/model/3980524/manuals

page 178 in the huge manual
the coverage is weak, HP style, I see no full error documents there
they only say call them.

This is problem with the starwheel assembly, make sure that there is no paper stuck under it and restricting movement. The starwheel is the metal bar and little spiky metal wheels that guide the paper.

21:2.13 error- service station fail- these can be ordered but need fitting by an approved engineer
part number CH538-67040

There is a problem with the "service station".
You are going to need a tech to look at it.

error 22.2.10 on t770 what is the problem

It's a "star wheel motor" error.
Try unplugging power cord from wall.
Plug it back in and power on.
If error persists, a technician is going to have to troubleshoot the printer.

A 59.2:00 error says that a reused part has been installed.
If you paid for a NEW formatter get your money back and shop somewhere else.
If you paid for a repaired/reconditioned part, it won't work.
You need a NEW formatter.

Did it ever work?

You are using the Post Script drivers, right?
Power down the printer from the back. Disconnect the power cord. Plug it back in and power it up.
Check the graphic language setting of the printer(look at the User Guide)
Resend the file.
Upgrade the firmware to the latest version (www.hp.com/#support)

YOU INSTALL THE DRIVERShttp://cluetechnologies.com/index.php?board=16.0