Siemens Microfloppy FDD100-5 Operating And Maintenance Manual page 49

5.6.2 DRIVE MOTOR ASSEMBLY
To remove and reinstall the drive motor assembly, use the following procedure:
A. Remove drive belt (item 25) (remove from large pulley first).
B. Disconnect connector P6-2 from servo control PWB (item 3).
Cut wire ties to free drive motor wires.
C. Remove head cable connector, four screws (item 84) which
attach PWB and fold back main PWB (about 120°).
D. Remove drive motor mounting screws and washers (items 68, 69,
& 70).
E. Remove drive motor and carefully route wires through hole in
disk drive main frame.
F. Reinstall by reversing steps A-E and replace wire ties.
G. Adjust motor speed (see paragraphs 5.8.1 & 5.8.2).
5.6.3 STEPPER MOTOR AND LEAD SCREW
To remove and reinstall the stepper motor and lead screw, use the following procedure:
A. Remove head cable connector and main harness connectors.
B. Remove four screws (item 84) which attach PWB and remove PWB.
C. Remove two screws, washers and motor clamps (items 64, 65 and
66) that attach stepper motor.
D. Remove E-ring (item 61) and washer (item 62) from front end
of lead screw.
E. Remove stepper motor through back by gently turning lead screw
in a counterclockwise (CCW) direction, as viewed from back of
motor, to disengage head/carriage assembly.
F. Reinstall by reversing steps A-E. When replacing antibacklash nut
and spring (item 51) it must be positioned with 0.010-0.030 inch
(0.0254-0,0762 cm) clearance between anti backwash nut and
carriage. (figure 5-2).
G. Adjust head radial alignment (see paragraph 5.8.6).
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