IBM 3270 Maintenance Manual page 244

You have gone through he PICs without solving
you problem. The following steps should help
you find additional audio or visual symptoms.
1.
Check the entire system for loose or damaged
connectors.
2. Return to page 3-5-1 and review "Start".
3.
Select "UTILITIES" in the diagnostic menu,
start an error log, and select "RUN TESTS
MULTIPLE TIMES". This will allow you to
operate the machine thoroughly and identify
the failing symptom. When you have
identified the symptom, go to the page 3-5-1,
"Start", or the appropriate PIC for the
symptom you received.
If you have followed these procedures and still
have an unsolved problem, you should request
technical assistance.
October
1984
3-700-5