Pressure Pad Actuator; Head And Pressure Pad Cleaning; Leadscrew Dust Cover (If Installed) - IBM System/32 Introduction And Maintenance Manual

3.2.9 Pressure Pad Actuator
Removal and Replacement
1.
2.
Turn power off at the operator control panel.
Remove the 33FD from the machine (3.2.5).
3. Remove the covers (3.2.8).
4. Remove two screws
It .
5.
6.
Remove leads.
Replace actuator, leads, and cover, and do
adjustment.
CAUTION
Adjustment
1. Turn power off at the operator control panel.
2. Remove the 33FD from the machine (3.2.5);
then turn the power on.
3.
4.
5.
Insert a diskette.
Energize the head load coil by installing a
jumper between the ground
II
and head
load
II
test points on the file control card
located on the 33FD.
a. On the old style file control card (2 wide,
3 high), test points are located randomly
on the component side of the card.
b. On the new style file control card (2 wide,
2 high), test points are brought out to two
rows of pins labeled TPA and TPB. For
the location of other test points, see 3.2.24.
Adjust the screw
II
until the pressure pad
arm and bail just touch
m .
6.
Rotate adjusting screw clockwise 112 to 3/4
turn and check for clearance between the
arm and bail at all tracks
II .
7. Install the 33FD in the machine.
Old Style File Control Card
Erase Current
+5 Vdc
r . . - - - - - - - - - + Preamp TP2
- Head Load
r----.,='T-r'7"T---+---+
+
Head Engage
r----+---==t +
Write Data
- - + MC-1
--+MC-2
----+MC-3
MC-O
-T-----\i--::-;:---=-+
P rea m p TP 1
;~------"'--+ Ground
- - - + LED Current
. - - - - - - - +
Access 0
I
New Style File Control Card
TPB
TPA
3.2.10 Head and Pressure Pad Cleaning
CAUTION
Use only the materials listed below to clean head
and pressure pad.
1. Turn power off at the control operator panel.
2. Remove the 33FD from the machine (3.2.5).
3.
4.
5.
With cover open, manually rotate the stepper
motor wheel until the carriage assembly is at
the upper limit stop. Remove the leadscrew
dust cover (if installed) (3.2.10.1).
CAUTION
Do not allow pressure pad arm to snap
against the head.
Pivot the pressure pad arm away from the
head and check pad for contamination. If
contaminated, use dry brush (PIN 22Q0106)
to remove caked deposits and to fluff pad.
CAUTION
Fluid treated cloth should not contact the
pressure pad.
While holding the pressure pad arm out,
clean polished head surface with isopropyl
alcohol (PIN 2200200) applied to a clean
cloth (PIN 2108930). Replace the leadscrew
dust cover (if previously removed) (3.2.10.1).
3.2.10.1 Leadscrew Dust Cover (if installed)
Removal
1. Remove the file control card.
2.
3.
Remove the dust cover, retainer spring and
wires.
Remove the dust cover.
m
Diskette
I
33FD Diskette Drive 3-13