NEC SuperScript 150C User Manual page 56

After cleaning the print head/print head carriage, print a
"demo" page to check the print quality. If the print quality is
still not acceptable, run a print test through the Printer
Monitor (see Chapter 1 - User Interface).
Make sure that the print head is inserted and that there
is paper in the ASF.
Once the test is completed and the sheet of paper expelled,
the printer will go automatically into ON-LINE condition.
Check the print quality of the test, making sure that all the
characters are clearly defined and complete.
If you have any problems running the print test, check
that you have followed the operating procedures
correctly.
Monochrome print test contents
The monochrome print test contains information on the
printer firmware (release, emulation and character
generators) and the correct operation of the print head
nozzles:
The first line of the print test contains technical
information on the printer status.
The second line of print test indicates the print head type.
The third line of the print test (Print Head Test), consists
of a diagonal line, indicating the performance of the
head nozzles, and the result line (Pass, or Fail with the
5-6 Troubleshooting