Oki ML520 Service Manual page 209

4.8.02 Rolling ASCII Test
General Information
The rolling ASCII test is a continuous printout of all 96 ASCII characters.
Use this test to check the following items.
1. Print Quality
Across the entire length of a line
Down the entire page
2. Line Spacing
3. Left Margin Alignment
At the top of the test is the printer type (1), emulation (2), country (3), and firmware revision level (4). This
information is often required while performing service or when contacting Okidata. Have this test available
during your service call.
CAUTION
Before running this test, make sure that continuous feed paper is loaded.
If you are running this test on a Microline 521, use wide paper or have the page width set for 8.5" x 11" in
the printer menu.
Running the test without paper loaded or having the wrong width paper loaded will allow the printhead to
print on the platen. This will dirty the platen, cause excessive wear on the ribbon, and may damage the
platen, ribbon, and printhead.
Procedure
Follow these steps to print the Rolling ASCII Test.
1. Load the correct size continuous feed paper.
2. Power off the printer.
3. Press and hold the QUIET switch while powering on the printer. You must hold the QUIET switch until
the test starts to print.
4. The test will continue to print until you press the SEL switch or run out of paper.
Service Guide ML520/521
Chapter 4 Failure & Repair Analysis
Page: 144