Keyboard Lockup; Transmit Errors - IBM Selectric Maintenance Manual

sion to the current level wi II be required. Time and
parts for this conversion may be charged to Code 32.
B/M 1280498 includes the following parts:
Ref. Part No. Description
1 1164310 Pu lIey, Ti It
2 1128455 Stud, Ti It Pu lIey{redesigned}
3 1164099 Washer, Fe It
4 1164158 Washer, Spacer
When orderi ng the above bi
II
of materi a I, it wi
II
be
necessary to order a new ti It tape to be used in con-
junction with the above bi
II.
The new ti It tape part
numbers are as follows:
Figure 16.0
Ref.
5
5
Part No.
1164314
1164316
4 _ _ ....
l1li
Description
Tape, 11" Printers
Tape, 15" Printers
5
Installation: Since the new pulley is heavier, it may
be necessary to use two spacer washers to provide suf-
ficient clearance between the pulley and the yoke in
tilt 3 position. The mounting stud should be lubricated
with IBM #23 grease and the felt washer kept dry.
The purpose of this washer is to keep erasures out of
the pivot bushing.
MECHANICAL KEYBOARD LOCKUP
17.0 Mechanical Keyboard Lockup
17.1 The most common causes for Keyboard Lockup are:
a. The Cycle Clutch Latch Link Pawl doesn't clear
the keeper with an interposer latched down.
(Section 1O.0).
b. Fi Iter shaft timing adjustment.
c. Cyc Ie shaft overthrow adjustment (Adjustment
4.5).
17.2
d. Latch motion restricted by restori ng ro lIer .
{Section 15.0}.
e. Cycle clutch adjustments - latch binding (Section
15.0).
f. Character interrupter adjustment. Old Style -
See Ref. Man. New Style - See 17.2:
g. The Linelock Interposer binds in the Selector
Compensator {clean and lubricate}.
KEYBOARD LOCKUP
Keyboard lockup wi II resu It from excessive overlap
of the cycle clutch pawl stop on the cycle clutch
pawl. All SELECTRIC I/O Printers should be checked
using a new specification of 1/3 to 1/2 overlap of
the pawl stop on the cycle clutch pawl {see illustra-
tion}. Be sure to maintain the .010" to .020" verti-
cal adjustment.
Cycle Clutch Pawl
.010" To .020"
Pawl Stop
-Figure 17.0
TRANSMIT ERRORS
18.0 Transmit Errors
18.1 S.H. TRANSMIT CONTACTS
The transmit contacts may be dirty. Clean with IBM
contact cleaning fluid, then wipe dry with clean
bond paper.
18.2 The transmit contact air gaps should be .020". -
18.3 The C 1 and C2 contacts must not bri dge {N/O and
N/C make at the same time.} For Cl and C2 timing
see the applicable systems Reference Manual.
18.4 PRINT SELECTION CONTACT ACTUATORS
If the contact actuators bind, they should be replaced
with the new style. The material used in manufact-
uring the contact actuators has been changed from
a clear translucent nylon to a cloudy, yellowish,
fiber nylon. The finish of the actuator plates has
been changed from nickel to chrome to provide more
reliable operation of the actuators. When replacing
an old style actuator with a new style actuator, the
actuator plate must ALSO be changed. Only' new
style actuator plates are available for field replace-
ment. All part numbers remain the same.
4-25