IBM 3274 51C Maintenance Information page 271

PTXCP
5 1
TPA10
1
0 00
01
!
D
TPA08 eJumper
o
TPA07 0 TPA06TPB02 (Ground) TPA
--
o '0
TPA01
0
0
TPB06 0 0 0 0 0 TPB01 TPB
TPB07 TPC03 0 0 0 TPC01 TPC
TPD020 TPD
0 0
1
0
0 0
0 0
0
TPE01
0
0 0
0
TPF01
0 0
0
TPG01
0 0
0
TPH01
0 0 0
TPLD2
0 0
0 0 0
TPLD1
0
0
0 0
0 0
0
0
8
0
0
110 CP
o
0
0 0
0 0 18
B A
D
~
6 1
1 00
0 01
SCP
LEDCP
4
100 01
Figure F-23. Control Card
F.3.2.2 Head/Carriage Adjustment (Figure F-24)
Warning: The head/carriage assembly adjustment must be
performed with the diskette installed (or in the same posi-
tion as when installed), or the adjustment might not be
accurate.
1. Power down.
2. Remove the cable guide
6) .
3. Measure and record the gap
0
between the stepper
motor pulley
0
and the casting.
Gapis: _______________________________________ ....
4. Loosen the clamp screw
CD
so the stepper motor
drive shaft
0
can turn inside the pulley
0 .
5. Turn the stepper pulley
0
by hand to track 40, and
insert the timing pin
O.
(Ensure that the pin goes
into the casting.)
I
DANGER
Voltage is still present at the socket when the power
cable is disconnected.
6. Disconnect the ac drive motor power cable
G.
7. Power up.
8. To disable the stepper motor, install a jumper
G
from TPA05 (ground) to TH05 (-'disable stepper
motor).
9. To locate the stepper motor at track 40, connect a
jumper from TPA07 (ground) to TPA04 (MC·O).
F-28
TPE
TPF
TPG
TPH
6
SMCP
0000
01
TPAMP20
o
TPAMP1
D
o
TPCTO
o
TPCT1
14 HCP 1
1 0 0 0 0 0 0 0 0 0 0 0 0
OJ
Warning: When the stepper motor pulley
0
is tightened
by the clamp screw
«D
ensure that the pin located on the
back of the stepper motor pulley remains within the cutout
slot on the casting.
1 O. Make the gap
4)
t~e
same size as the gap recorded in
step 3, and tighten the clamp screw
O.
(Ensure that
the timing pin passes freely through the stepper motor
pulley into the hole in the casting.) The clamp
G
should be placed even with the end of the stepper
motor drive shaft
0 .
11. Remove the timing Pin • .
12. Loosen the two bracket-to·carriage clamping screws
e.
13. Remove the jumper end from TPA04, and install the
jumper end on TPH01 (MC·3).
14. Remove the jumper end from TPA01, and connect the
jumper end on TPA04 (MC·O).
15. Verify that this is track 40 by visually checking that the
timing hole in the pulley lines up with the timing hole
in the casting. (Use the dental mirror to check; do not
use a timing pin.)
16. Insert a 0.508 mm (0.020 inch) thickness gauge
e .
between the timing pointer on the carriage and the track
40 adjustment surface on the casting. Use the clip
(PN 4240632)
CD
to attach the thickness gauge to the
casting. The clip is attached to the diskette guide (see
Figure F·4).