IBM 5280 Maintenance Information Manual page 106

341
HEAD/CARRIAGE REMOVAL AND
REPLACEMENT
Removal
1.
2.
3.
Power off.
Remove the head cable connector
fII
from the
diskette drive control card
Em
and remove the head
cable from the cable guide
fa .
Remove the cable guide
fa .
CAUTION
The drive band must not be bent or damaged in any way.
4. Remove the two screws
iii
and the screw
II,
then remove the drive band
m.
(Note the position
of the drive band and the clamps; they must be in
the same position when reinstalled.)
5. Remove the carriage bracket
II
from the carriage.
6.
(51TO) Place a piece of clean paper between the heads.
7.
8.
Remove the two screws
m
(one on each end of
guide rod
D)
and remove guide ·rod
D.
Lift and turn the head/carriage assembly to remove
it from guide rod
lID .
Replacement
CAUTION
When installing the head/carriage assembly, ensure that the
bail is under the tab of the carriage arm, the bail return
spring is properly installed, and the drive band is not
damaged in any way. (51 TO) Ensure that a strip of clean
paper is inserted between the head surfaces during
installation.
341
1.
2.
3.
4.
5.
6.
Reinstall the head/carriage assembly on guide rod
1m .
Then place the head/carriage assembly to the
lower limit (track 00).
Reinstall guide rod
D
and tighten the two screws.
Ensure that the guide rod notch
lEI
is aligned with
the screw.
Move the head/carriage assembly by hand to track
40.
Reinstall the carriage bracket on the carriage with
the screws installed in the center of the hole.
Connect the welded adapter end of the drive band
III
to the slotted end of the carriage bracket. Use
the clamp
1m
to install the drive band to the stepper
motor pulley. Ensure that the drive band is parallel
to the carriage bracket and the edge of the pulley.
Block the head/carriage assembly approximately 25
millimeters (1 inch) from the casting
1m .
7. Pull on the welded adapter end of the drive band
ID
with 2.5
±
0.25 pounds of force (use gauge
1m,
part 460870) and tighten the band clamping screw.
Ensure that the drive band is parallel to the stepper
motor pulley edge.
8. Remove the block from between the casting and
the head/carriage assembly.
9. (51TO) Remove the paper from between the heads.
10. Move the head/carriage assembly back and forth by
hand and ensure that the drive band tracks straight
and that the drive band is parallel to the stepper
motor pulley edge (see 361).
11. Connect the head cable connector to the diskette
drive control card.
12. Turn the stepper motor pulley by hand to track 40
and insert the timing pin.
Head/Carriage Assembly 15