Service Checks - IBM 1620 Manual

SERVICE CHECKS
A. MOTOR AND DRIVE
1. Coasts freely when power is turned off.
2. Belts and pulleys are aligned correctly.
3. 1/4
11
belt deflection.
4. Power roll end play is correct (.002
11
-
.010
1I
)
B. CARRIAGE
1. Freedom of movement - No play
2. No loose parts - particularly margin and
tab rack.
3. Carriage tension and carriage return tape.
4. Platen turns freely when not detented.
5. Pin wheels do not bind.
C. TYPEBARS
1. Use type al ignment sample (B-1 Ref. Manual,
Page 5)
2. No binds or loose type slugs.
D. ESCAPEMENT
1. Fast, unhesitating action over the full length
of the carriage (space across several times).
2. All typebars trip the escapement pawl as they
enter the type guide.
E. CARRIAGE RETURN
1. Positive return from any carriage position with
line space lever at three (3).
2. Impact is cushioned before striking left margin.
3. No excessive whip of the carriage return tape
on successive carriage returns.
4. Carriage return clutch plate to operating arm
clearance (.005
11
-
.015
11
) .
F. BACKSPACE
1. Backspace complete length of carriage.
2. Carriage does not lock up when backspace and
carriage return key are depressed simul taneously.
G. TAB
1. Tab check lever two (2) spaces to the right of
the tab stop on long and short tabulations.
2. Tab speed about the same as carriage return
speed.
3.9
H. RIBBON MECHANISM
1. Reverses easily on both sides.
2. Feed pawls feed two (2) full teeth on ribbon
spools.
3. Ribbon lift guide is not binding.
4. All characters strike the ribbon in both upper
and lower position of the color control lever.
·1. SHIFT
1. Equal distance (1/16
11
)
between pusher and
upper and lower pins on the shift actuating
plate.
2. Shift lock holds the basket securely (up and
down).
3. All characters have even impression (top and
bottom) in either shift position.
J.
SOLENOIDS
1. Remove and clean space, tab, C.R. solenoid
plungers.
2. With plungers bottom, key lever should be 1/32 11
from the bottom of the slot with cam just tripped.
3. Plunger spring hooks are centered in key lever
slots.
4. With power off, cam release lever of a tripped
functional cam should rest midway on the cam
log.
K. MAGNET UNIT
1 • Armatures and push rods do not stick or bind.
2. All amatures resul t in a smooth typing speed.
3. Armature to stop bail clearance (.070
11
)
4. Cam to power roll clearance (light drag on two
IBM cards).
L. INTERLOCK CONTACTS
1. Contacts are clean and remain closed for the
full duration of the operation.