IBM 3270 Maintenance Manual page 215

1. Remove your diskette .
• For a Type 1 diskette drive, check the
voltage from TP-7 to ground while
'inserting a diskette. The voltage should
decrease from approximately
5.0
V dc to
approximately 0 Vdc as you insert the
diskette.
• For a Type
2
diskette drive, check that the
voltage between U6 of pin 5 and ground
decreases from approximately
5.0
V dc to
approximately 0 Vdc as you insert the
diskette.
Tvpe 1
U6
Tvpe2
DID THE VOLTAGE DECREASE TO
APPROXIMATELY 0 Vdc?
NO Replace the diskette-drive. (see Section 5,
"Removal/Replacement and Adjustments").
YES
3-600-16
Maintenance Information