IBM 3270 Maintenance Manual page 418

1. Check that your meter is set to the 12 V dc
scale.
2. Measure the voltage between the system
board power connectors listed below.
Voltage Connectors
Min Vdc
Max Vdc -Lead
+
4.8 +
5.2
5
+
4.5
+
5.4
9
+
11.5
+
12.6
7
+
10.8
+
12.9 4
ARE THE VOLTAGES CORRECT?
+
Lead
10
6
3
8
NO Replace the power supply. See Section 5,
"Removal/Replacement and Adjustments."
YES
October 1984 3-9999-13