IBM 3270 Maintenance Manual page 211

1. Set the Power switch on the system unit (and
expansion unit, if attached) to Off for 5
seconds.
2. Ensure the terminating resistor is correctly
inserted. It should be in the logic board of
drive A and not in the logic board of drive B
(see Section
4,
"Locations").
3. Set the Power switch on the expansion unit
(if attached) and the system unit to On.
Terminating Resistor
Type 1
Type 2
CONTINUE
3-600-12
Maintenance Information