IBM 3270 Maintenance Manual page 95

1.
Remove the jumper that is between pin 2 and
pin 4 of the display signal connector.
2. Measure the voltage between pin 2 and pin 8.
The correct voltage is shown below.
Pin Name Voltage
8
Horizontal
0.0 to 1.2
Sync
Vdc
System Unit
o
o
IS'THE VOLTAGE CORRECT?
YES
Replace the display unit. See Section 5,
"Removal/Replacement and Adjustments."
NO Replace the display adapter. See Section
5, "Removal/Replacement and
Adjustments. "
3-25-20 Maintenance Information