Lexmark 4I3 - Manual (Page 216)

Printer Verification
You can test general print quality and the wires in the print head by
using the Printer Verification test. This test prints nine horizontal
lines using each wire on the print head. After these nine lines have
printed, several lines of data processing (DP) characters are printed
followed by several lines of near letter quality (NLQ) characters.
To test print quality, follow these steps:
1. Enter the Operator Print Tests (see “General Test Instructions”
on page 5-1).
The printer displays
2. Press Scroll or Scroll until the printer displays
3. Press Enter or Start to begin the test.
The Ready indicator goes on and printing begins. The
verification printout is complete when the Ready indicator goes
off.
OPERATOR PRINT TESTS
Printer Demonstration
OPERATOR PRINT TESTS
Printer Verification
5-16 User’s Guide