IBM 3274 51C Maintenance Information page 246

Appendix F. IBM 51TD Diskette Drive Maintenance
Safety Information
The CE Safety practices, located at the front of this manual
should be reviewed before you service the 51TD Diskette '
Drive. To prevent personal injury and machine damage,
observe all DANGER, CAUTION, and Warning notices,
making sure you fully understand them.
AC voltages are present on the 51TD drive motor connector
and capacitor terminals when the drive motor is running.
The motor and the solenoid become hot after continuous
use; let the parts cool before attempting servicing. The
following, DANGER, CAUTION, and Warning notices
appear in this appendix in the sequence shown:
I
DANGER
Input ac voltage is present in the prime power box when
the 3274 I/O (on/off) switch is in the 0 (off) position.
I
DANGER
Voltage is still present at the socket when the power
cable is disconnected.
I DANGER
High voltage may be present at the capacitor terminals.
CAUTION
The motor case becomes hot after continuous use.
CAUTION
The solenoid case becomes hot after continuous use.
Warning: Do not attempt to remove the collet/flat spring
befnre removint' IiI. Too much pressure or binding can
damage the sprillY.
Warning: Ensure that the heads do not hit each other when
the bail is removed from under the head arm.
Warning: Too much pressure or binding of the flat spring
will damage the spring.
Warning: The head/carriage assembly is adjusted and tested
at the factory. Do not attempt to adjust or repair any part
of this assembly.
Warning: The head/carriage assembly adjustment check
must be performed with the diskette drive installed (or with
the diskette drive in the same position as when installed) or
the adjustment might not be accurate.
Warning: The stepper drive band assembly can be easily
damaged. Do not bend, crease, or scratch the band. Do not
use a damaged band.
Warning: When you install the head/carriage assembly,
ensure that a strip of clean paper is placed between the
diskette drive heads to protect them during installation;
also ensure that the bail is under the head load arm. Ensure
that the bail return spring is correctly installed. Ensure that
the band is not damaged in any way.
Warning: Do not let the solenoid plunger and cable turn
while you make the bail adjustment.
Warning: When the stepper motor pulley is tightened by the
clamp screw, ensure that the pinJocated on the back of the
stepper motor pulley remains within the cutout slot on the
casting.
Warning: Be careful not to damage the control card.
Appendix F. IBM 51TD Diskette Drive Maintenance F-l