IBM Personal Computer XT Manual To Operations page 162

5
Perform the printer self-test:
1. Press and hold the Line Feed button while
you set the printer's Power switch to On.
2. When the test starts, release the Line Feed /..............
button.
Note: The printer self-test takes
approximately 10 minutes.
3. To stop the test before it finishes, set the
printer's Power switch to Off.
8000-2 Test April 1984