IBM 3270 Maintenance Manual page 172

Check the first character of your error code.
ENTER THE NUMBER(S) OF OPTIONS TO TEST
OR PRESS ENTER TO SELECT ALL OPTIONS
?2
TESTING - XXXKB MEMORY
THIS TEST TAKES UP TO TWO MINUTES
PLEASE STAND BY
ERROR - XXXKB MEMORY 201 S
XX:XX:XX
!
FAILING ADDRESS - SPACE/MODULE XXXX XX
PRESS ENTER TO CONTINUE
IS THE FIRST CHARACTER OF YOUR
ERROR CODE A 4?
NO Go to page 3-200-49
YES
October 1984 3-200-47