IBM 3151 Manual To Operations page 109

Analysis Procedures
5. Press and hold the
Ctrl
and
Shift
keys, then press the Hold key.
Does the test pattern appear on the screen as shown
Oil
page 5-17?
Yes Go to step 6.
No The keyboard is failing. Replace the keyboard. See page 5-20.
6. Compare all characters of the test pattern shown on page 5-17 with your
screen.
Do all characters match?
Yes Go to step 7.
No The video element is failing. Replace the video element. See page 5-20.
7. Observe the keyboard ID on the screen (see page 5-17).
Does the keyboard ID match the ID for your keyboard?
Yes Go to step 8.
No The keyboard is failing. Replace the keyboard. See page 5-20.
8. While observing the screen, repeatedly press any key or the key that did not
work.
Does only one corresponding position in the screen change from
0
to
I!I
or vice
versa?
Yes Go to "Communication Problems" on page 5-19.
No The keyboard is failing. Replace the keyboard. See page 5-20.
5-16
IBM3151· Guide to Operations