IBM 3270 Maintenance Manual page 102

You pressed 0, but the menu did not appear.
Press the other numeric keys at the top of the
keyboard.
ARE ANY OF THE NUMERIC KEYS AT THE
TOP OF THE KEYBOARD FUNCTIONING?
YES Replace the keyboard. See Section 5,
"Removal/Replacement and Adj ustments."
NO Replace the keyboard/timer adapter. See
Section 5, "Removal/Replacement and
Adjustments. "
October 1984 3-90-5