Ibm 1620 User manual

)

1620 SERVICE INDEX

INTRODUCTION

The 1620

Service

Index

is

designed

to

guide

Customer Engineers

toward

a

logical

and

rapid

solution

to system

failures.

It

is

intended

that

function

charts,

logics,

reference

manuals,

etc.

be

used in

connection

with

the

Service

Index.

Each

section

of

the

Service

Index

is

indexed

separately

and

i'ncludes

individual

page

and

figure numbering

to

permit

rapid

access

to

the

specific

information

needed

by

the

Customer

Engineer.

1.1

See

Core

Storage

Section

-

Page

4-2

See

MAR

Section

Page

5-2

See

I/o

Section

1622

-

Page

3-1

6

See

Power

Supply

Section

-

Page

6-2

See

I/O

Section

Typewriter

-

Page

3 - 2

See

I/o

Section

1621

-

Page

3-10

See

I/O

Section

1624

-

Page

3-1

5

"'---

-_/

--.--

See

General

Trouble

Shooting

Section

-

Page

2-2

See

Fortran

Section

-

Page

7- 2

1.2

GENERAL

TROUBLE-SHOOTING

INFORMATION

2.

1

CHECK

LIST

I.

General

Information

A.

On

what

operation

does the machine fai

I?

1.

DFT

2.

Customer work (Fortran,

etc.)

3.

Op

code

of

failure

B.

What

is

the

frequency

of

error?

1.

Time

of

day

2.

Environment

(temperature,

etc.)

3.

Does customer power

fluctuate

at

certain

time

of

day?

(welder,

heavy

machinery,

etc

.)

II.

General

Check

List

A.

Have you

checked

for loose

or

bent

connectors?

1.

32 pin connectors

(x,

y,

etc.)

2.

Edge

connec

tors.

3.

Laminar buss (pins and terminals)

4.

TB

connectors (power

supply,

power

sequence,

etc.)

B. Have you

checked

for grounds?

1.

DC

isolated ground

2.

AC

isolated ground

3.

Ground straps (check

contact

from the

gate

to the frame)

C.

Have you

checked

the

Power Suppl

ies?

1.

Voltage

levels

2.

Ripple

D.

Have you

checked

Muffin

fans?

1.

Power supply fans

2.

Gate

fans

E. Does the machine fai I on margins?

1.

Normal margins ± 15%

2•

:::30'10

ma

rg

ins

*3.

Heat

*4.

Cold

*Steps 3 and 4

are

last

ditch

efforts

and

should

be

used

only

after

all

otherprocedures

fail (See

Note

1).

III.Core Storage

Check

List

A.

Have you

checked

the

difference

voltage

using

1/4%

accurate

meter?

B.

What

lights

are

on?

C.

What

is

the

pattern

of

the fai

lure?

1.

Greater

or

less than 50; odd

or

even,

etc.

2.

Picking

or

dropping bits

3.

What

bits

are

affected?

D.

Is

the trouble in

MBR

rather than memory?

E. Memory Temperature 1000 ±30 (Muffin Fan)

F.

Have you seoped (using

current

probe)?

1.

x,y

drive

lines

2.

z (inhibit)

drive

lines

2.2

3.

Decode

Output

4.

Current

driver

outputs

5.

All Iines to the inductors

G.

Have you scoped the sense lines (usi

ng

a 535

or

equivalent

scope

and

a type

IIDII

High

Gain

Differential Pre-amp plug in

unit)?

H.

Have you

checked

the physical wiring of the

indicators?

I.

Have you followed scope procedures

i,n

1620

CE

Reference

Manual?

IV.

MAR

Check List

A.

What

console lights

are

on?

1.

Op

code

of

failure

2.

code

3.

IIEII

or

11111

cycle

trigger

of

failure

4.

Which register

failed

5.

Fai lure to

read,

or

write

6.

Is

the trouble in

MAR

triggers

7.

Is

the

trouble in

Inc.

Dec.

switch

8.

Is

the trouble in

Multiply

Register

or

TiC

Circuits.

B. Have you scoped (using a

current

probe)?

1.

Read drivers to

all

registers

2.

Sense lines

3.

Write drivers to

all

registers

4.

Bit drivers

Note

1:

If

errors do

not

become more frequent with

marginal

check

part

(lor

2),

block

the

fans and

let

the

gates

heat

up.

If

part

3 does

not

solve

the

problem,

obtain

about

501bs.

of

dry

ice,

remove

the

filters from the

gate,

place

the

dry

ice

on the

floor,

then

construct

a skirt

out

of

paper

and cause

all

the

air

to

be

drawn

from

around the dry

ice.

Note

2:

Observe

the function

of

the

IIEII

or

'"1

11

cycle

trigger

to determine

the

register

affected.

Under some

triggers,

more than

one

register

is

affected.

Be

critical

of

the timing of the pulses on these

lines.

If the

fail-

ure occurs

while

writing,

it

will

be

detected

at

the

time

it

is

read

out.

In

order

to determine the

cause,

scoping must

be

done

at

the time

of

writing.

Some

intermediate

checks

can

be

performed by use of the

MAR

Display Switch, by stopping

at

different

trigger

times and displaying the register in

question.

Check

to

be

sure

that

only the registers

called

for by a trigger

are

being

operated

on.

TRANSIENT

POWER

LINE NOISE

The

only

pattern

that

can

be

associated

with

noise

is

its

lack

of

a

pattern.

If

transient

noise

is

suspected,

the

Physical Planning Department should

be

alerted

to

the

situation.

Listed below

are

some common symptoms

noted in

the

field:

1)

High

Iy

intermittent

failures

2)

Failure

defies

any

analysis by

pattern

3) Failures

occur

mostly during

the

day

(commonly

start

or

end

of

a work

day

when

large numbers

of

equipment

are

being

turned

On

or

Off).

4)

Week

end performance

relatively

trouble

free.

Areas in the 1620 system most noise

sensitive:

1)

1622 units tens ring

2) Binary triggers

3) Drift

latches

Methods

of

determine

noise:

1)

Scope

a.

Suspected line

b.

"J"

pins

SMS

Panels

containing

failures

c.

AC

input

Iines

at

contactors

2)

Indicator

- A

drift

latch

may

be

wired into

circuit

and

gated

to

indicate

a

transient

pulse.

One

of

the

test

lamps (Tl

or

T2)

on 1620

console

could

reflect

status

of

th

is

latch.

3)

New

Input -

Run

in temporary

cable

from building

serviceto

1620.

This

will

give

the

CE

a power

line

free

of

building

transients.

Methods

of

aggravating

noise problems:

1)

Determine

other

equipment

on

the

1620

line.

Run

a

program

while

throwing

On/Off

switchs on this

equipment,

i.e.,

air-conditioning

units,

heaters,

other

DP

equipment,

etc.

2)

Separate

AC

and

DC

isolated ground from machine

frame.

Areas to

investigate

if noise problems

are

encountered

or

suspec

ted:

1)

Is

system on

separate

power

line?

2) Does system

have

a good ground return to power

source (in most cases condu

it

ground

is

not

satis-

factory)?

2.3

INPUT

-

OUTPUT

Typewriter

Read

Checks

Write

Checks

Known

Trouble

Tip

s

Service

Checks

1621-1624

1622

Read

Checks

Write

Checks

Read

Checks

Reader

Checks

(off

line)

Write

Checks

Punch

Checks

(off

line)

Known

Trouble

Tips

Service

Hints

1620-1622

Data

Transfer

Charts

3.

1

3. 2

3.4

3. 5

3.9

3.

10

3.

15

3.

16

3.

17

3.

18

3.

19

3.

20

3.22

3.31

1)

2)

3)

4)

Check

transfer to

MDR

If

Op

37

check

set

of

MBR

from

zone

translator

Read

Checks

Typewriter

READ

Checks

MBR

and

READ

Checks

Refer to Section

IV

(Core Storage)

MBR

check

may be

caused

by invalid

data

in memory

1)

Check

Typewriter Bit Relays

2)

Check

input

translator

3)

Check

typewriter

keyboard

contacts

and

selector

common

(False Read

Check)

Check

VRC

Circuit

contacts

(Timing Relationship

pg.

3.3)

Scoping Methods

1)

The

input

translator

may

be

scoped by

blocking

a

typebar

in its fully raised position

with

the

type-

writer

on-off

switch in

the

off

position.

At

this

time,

the

input

translator

is

conditioned

to

accept

the

bit{s) corresponding to

the

typebar

raised.

2) The·transfer to MDR, and from

MDR

to

MBR,

may

be

scoped by

blocking

a

bit

relay

or

group

of

relays transferred and locking

the

system in a

trigger

30

operation.

To

lock in a

trigger

30

operation,

block

the

"B"

advance

pulse

which

turns on

the

hold

trigger.

3.2

w

Trouble

1)

MAR

incrementing when flag

key

is

depressed

or

extra

digits

being

set

in memory

(i.e.,

having 1223

set

in memory

after

keying in

123.)

2)

a.

Skipped

I/O

Instructions

b.

Multiple

I

Cycle

Triggers

c.

E and I

Cycle

Probable Cause

1)

a.

Check

for a broken spring on the

left

end

of

the ribbon

lift

bail.

b.

Selector

Common

Contacts

and

Typewriter

Magnet

Armature

contacts

maladiusted.

The

following relationship should

exist:

Magnet

Armature

Contact

45-60

mill iseconds

I

+7.5

mill iseconds

t I

5milli-

r i 5

milli-

I;;..

I

~

seconds

seconds I I

I l

I ,

Selector

Common'

Contact

#1

39

rgill ifr-conds ,

I

+.

ml

Iseconds I

I i

5milli-

I , 5

milli-

seconds

>-

< seconds

•

Selector

Common

Conlact

#2 12-18

mi

II

iseconds

I

2)

a.

Check

carriage

return

contact

to insure

that

the

N/O

contact

has a minimum

of

.010

rise from its support strap during

entire

length

of

carriage

return.

b.

Check

tab

interlock

contact

to insure

that

the

N/O

strap has

.020

"To

.030"

contact

rise.

Write

Check

Typewriter

r-

ves

-(

C~!:k

)-NO

1)

See

Memory

Trouble-

shooting

Information

(Page

4.2)

~-.

No

1)

Check

Typewriter

Mag.

Arm.

2)

Check

Typewriter

Mag.

3)

Check

Relay

Network

for

defective

Relay Point(s)

Check

Bit

Relay Pick

Circuit

No

Yes

1)

Check

I/o Exit Trigger

Circuit

2)

I

Cycle

Entry

Circuit

3)

Check

Typewriter

to Insure

the

Mechanism for Printing

Last

Character

is

operating

properly

Yes

1)

Check

Write

Check

Trigger

and

Circuit

4)

Check

Letter

Cam

~--....Jl)

Check Selector comm}n Contact

#2

(False

Check)

~-NO

MDR

Correct

-vesl

1)

Check

for

correct

data

in memory

2)

Check

MDR

Trigger Reset

Circuit

3)

Check

MBR

to

MDR

Transfer

Servicing

Approach:

1)

Check

MDR

lines

to

translator

1)

Attempt

to

establish

a

failure

pattern

2) Load memory

with

most

consistent

failure

pattern

3) Sync on

CR

5 for

typewriter

translator

failures

2)

Check

Translator

VRC

Circuit

3)

Check

Write

Check

Latch

4) Sync on Trigger

30

I sync

trigger

I

etc.

I for troubles

during

set

of

MDR.

3.4

KNOWN

TROU

BLE

TI

PS

Typewriter

Broken Typebars

Improper

setting

of

Impression Control

and/or

Mult-

iple

Copy

Control

can

contribute

to

excessive

type-

bar

breakage.

Operators

should be

advised

of

the

following

procedures

for

setting

the

above

controls.

Impression

Indicator.

The

lever

under

this window

can

be

positioned

in

setting

from ato

10

to

deter-

mine

the

force

with

which

the

typebars

strike

the

paper.

The

higher

the

indicator

setting,

the

harder

the

typebars

strike.

To

test

for the

correct

setting,

move

the

indicator

up until

the

comma

and

period

print

distinctly

but

not

heavily.

Use a

higher

setting

for

multiple

copies,

but

be

sure

that

the

multiple

copy

lever

is

also

correctly

set

before

finally

adjust-

ing

the

impression.

Multiple

Copy

Control.

This

lever

moves

the

platen

backward

to

compensate

for

the

greater

thickness

of

additional

copies.

As a

general

rule,

the

lever

should

be

set

at

IIA

II

for

one

to

three

copies

and

moved

back

one

position

for

each

additional

three

to

five

copies.

Heavy

print

at

the

top

of

characters

shows

that

the

platen

is

too

far

back;

heavy

print

at

the

bottom

of

characters

shows

that

the

platen

is

too

far

forward.

The

shilling

mark

(/)

is

a good

character

to use in

checking

multiple

copy

settings.

IMPRESSION

AND

TYPE

ALIGNMENT

VERY

WEAK

OR

NO

IMFRESSION

Multiple

c;opy

lever

in wrong

position.

Ribbon

color

control

button

in

stenci

I

position.

Wrong

platen

for thickness

of

form.

Platen

too

soft.

Improper

power

roll

speed.

Bind in

power

roll

and

drive

mechanism.

Ribbon

failing

to

feed

properly.

Oil

on

ribbon.

Ring

and

cylinder

out

of

adjustment.

Dirty

or

glazed

power

roll.

Power roll may

need

to

be

replaced.

Cam

Serration

worn

at

the

knockout

position.

~e

place

cam.

Loose

rubber

on

power

roll.

Improper

cam

clearance.

3.5

Dirt

in

segment

or

on

typebars

in

the

slots.

Impression

indicator

set

too

low.

Universal

bar

or

escapement

choking

off

typebar

action.

Impression

control

screws

set

too

light.

Type impression may

be

set

too I

ight

to

avoid

cut-

ting

the

paper.

Polish

the

type

faces.

INTERMITTENT LIGHT IMPRESSION

Dirt

in

segment.

Finger

prints

or

grease

on

paper.

Cam

serrations

worn

at

the

knockout

position.

Re-

place

cam.

Bind in

type

bar

linkage

or

type

guide.

Misadjustment

of

type

bar.

Worn

type

bar

or

universal

bar.

Loose

carriage.

Eccentric

power

roll

due

to loose

rubber.

Dirty

or

glazed

power

roll.

Power roll may

need

to

be

replaced.

CHARACTER

FAILS

TO

PRINT

Letter

cam

pivot

worn.

Armature

off

push

rod.

Bail

armature

stop too

far

forward.

Weak

magnet.

Low

voltage

shot

to

mag.

-(less

than

42 volts)

Typebar misal

igned.

Power roll

worn.

DIFFERENT HEIGHT

ON

END

TYPEBAR

Type

bar

guide

may

be

leaning

to

right

or

left.

OVERPRINTING

AND

UNDERPRINTING

Check

for

light

top

or

bottom.

Check

motion.

Improper

platen.

Cushion

of

paper

too

deep

in

the

form.

Check

mu

I

tiple

copy

lever.

Check

ring

and

cyl

inder

adjustment.

TYPE

CUTTING

Check

power

roll

speed.

Impression

indicator

set

too

high.

Platen

too

hard.

Check

ring

and

cyl

inder

adjustment.

Type may

need

polishing.

Impression

control

screws may

require

adjustment.

Some

papers

are

brittle

and

cut

too

easi

Iy.

Such

paper

may

be

reinforced

by using a

sheet

of

tough tissue

behind

the

original.

PILING

Insufficient

carriage

tension.

Improper

universal

bar

adjustment.

Dirt

in

segment.

Dirt

on

power

roll.

Escapement

tripping

too

late

or

too

early.

Dirt

in

carriage

ways

and

rails.

Worn

typebar.

Broken

or

worn

universal

bar.

It is

possible

for

an

operator

to

pile

the

type

by

uneven

rhythm

or

by

striking

two

or

more keys

nearly

simuI

taneously.

Strict

adherence

to

adjustment

procedures

will

minimize

this

occurrence.

PAPER

WRINKLING

Swollen

platen

and

feed

rolls.

Uneven

feed

roll

pressure.

Bent

deflectors.

Check

all

paper

feed

pointers.

Partial

feed

roll

contact.

CARRIAGE

RETURN

FAILS TO OPERATE

Faulty

cam

link

adjustment

Bind in

cam.

Back

space

pawl may

be

binding

the

interlock

which

wi

II

cause

carriage

return

fai

lure.

INCOMPLETE

RETURN

Fau Ity

cam

adjustment.

Escapement

pawl

pulled

too

far

out

of

the

rack.

lip

of

the

clutch

knockout

lever

adjusted

too

high.

Clutch

lever

bracket

adjusted

too

loosely.

Nut

on

compression

spring

under

machine

should

be

tightened.

Lack

of

tension

of

the

latch

spring.

Improper

cam

link

adjustment.

Improper

latch

adjustment.

CARRIAGE LOCKS

Latch Iink

adjustment

allows

too

deep

a

latch

en-

gagement.

Excessive

latch

spring

tension.

Weak

motor.

Bind in

power

roll

and

drive

mechanism.

Tip

of

clutch

knockout

lever

too

low.

Clutch

knockout

lever

Iink

adjusted

so

knockout

lever

is

too

low.

Margin

rack

adjustment

allows

too

much

overbank.

Clutch

lever

bracket

adjusted

too

tightly.

Adjusting

nut

on

compression

spring

adjusted

too

3.6

tightly.

Clutch

operating

arm

too

close.

Carriage

return

tape

off

pulley.

Truck

roller

or

star

wheel

binds.

Upper

I

ine

I~ck

Bellcrank

spring.

UNEVEN

MARGIN

Margin

rack

out

of

adjustment.

Broken

tab

lever

assembly

or

margin

stop.

Excapement

pawl

sticking

or

binding.

Weak

pawl

spring.

Air

cylinder

port

closed

too

much.

Carriage

return

contacts

maladjusted

or

bounc

ing.

Too

strong

carriage

return

-

especially

on

long

carriage

machines.

MOTOR

FAILS TO

START

OR

RUN

Faulty

condenser.

Check

by

turning

motor

by

hand.

FauI

ty

motor.

Broken

switch.

Switch Iink

improperly

adjusted.

Frozen

bearing.

Bel

ts

too

tight.

NOISE

TOP COVER VIBRATBS

Open

cover

and

spread

sides

sl

ightly.

REAR

COVER VIBRATES

Reposition

rear

cover.

CARRIAGE END COVERS

VIBRATE

Reform

spring

clips.

PAPER

TABLE

VIBRATES

Reset

positioning

coll<llrs.

NOISY

PAPER

BAIL

Check

for

broken

paper

bai

I

spring.

Reposition

bail

rolls

on

shaft.

NOISY

DRIVE

Check

motor

and

pu

lIey

lubrication.

Align

pulleys.

Replace

worn

belts.

Adjust

belts.

Check

power

roll

adjustment.

NOISY

TYPING

Typebar

hitting

front

scale.

Type

rest

pad

worn.

Platen

too

hard.

NOISY

SHIFT

Broken

shift

stop

bracket.

Broken

segment

gu

ide.

Cracked

bumper

on

shift

pusher.

Shift

stop screw rubbing

on

bracket.

NOISY

SPACE

BAR

Improper stop

bracket

adjustment.

Space

bar

mechanism

hitting

case.

Improper powI

release

lever

adjustment

allowing

escapement

pawls

to

drag.

NOISY

CARRIAGE REruRN

Improper

adjustment

of

the

eccentric

on

the

pawl

release

lever

allowing

the

pawls

to

drag.

Clutch

adjusted

to

return

the

carriage

too

hard.

SHIFT

INCOMPLETE SHIFT

Pusher too high

or

too

low.

Binds in

basket

or

shift

mechanism.

Excessive

or

uneven

clearance.

Broken

hairpin

spring.

Keybutton

binding.

FAILS TO SHIFT

Check

cam

adjustment.

Improper

clearance.

Pusher too high

or

too

low.

Improper

cam

link

adjustment

•

Lack

of

lubrication.

Cam

may

be

binding.

Shift

equal

izing

rod

out

of

place

or

warped.

Excessive

to

pusher

clearance.

Bind in

plunger

or

maladjusted.

Cam trip

lever

maladjusted.

Auxiliary

hairpin

spring

off.

MOTION

FAUllY

Improper

adjustment

or

adjusting

nuts.

Adjusting

lock

nuts.

Left

and

right-hand

shift

motion

adjustments

not

made

equal.

Test

with

strips

of

paper

between

the

stop washers

and

the

brackets

in

each

posi-

tion

of

the

basket.

Lock

nut

on stop

bracket

adjusting

screw

loose.

Broken stop

bracket

(basket

should rest

evenly

on

both

brackets

to

prevent

breakage).

Broken

segment

guide.

LIGHT TOP

OR

BOTTOM

Adjust

shift

stop

bracket

screws.

Wrong

platen

for thickness

of

form.

Copy

control

lever

set

at

improper

position.

3.7

Check

platen

guide

yokes for loose

platen.

SLOW OR

BOUNCING

SHIFT

Improper

cam

adjustment.

Improper

clearance.

Improper

pusher

adjustment.

Broken

pusher

buffer.

See

that

operator

is

not

"beating

the

shift".

Power roll

glazed.

Cam

bind.

Worn

cam.

TABULATION

FAILS

TO OPERATE

OR

TABULATES

ONLY

A

FEW

SPACES

Improper

cam

adjustment.

Fractured

cam

or

link.

Improper

key

lever

link

adjustment.

Tab

lever

not

being

pulled

far

enough to

latch.

Linkage too

long.

Improper

latch

adjustment.

Improper

latch

stop

adjustment.

Tab

lever

binding

on

margin

rack.

Bind in

tab

lever

fulcrum.

Improper

tab

rack

adjustment

which

may

cause

tab

lever

to

strike

tab

stop_

Tab

lever

stop

on

rear

rail

set

too

far

forward.

Friction

governor

adjustment

may

be

faulty

I

causing

a

bind.

Weak

tab

lever

spring may

prevent

tab

lever

from

restoring

properly.

Back

space

pawl may

be

binding

the

back

space

interlock

which

will

cause

tab

failure.

Lack

of

lubrication.

Excessive

cam

clearance.

Tab

latch

keeper

to

far

rear.

Trip Iink

maladjusted.

Plunger

maladjusted

or

binding.

Maladjusted

interlock

contacts.

TABU

LA

TES

SHORT

Tab rebound

check

lever

has

excessive

clearance

with

tab

stop.

Worn

tab

stop.

Tab

lever

moving too

far

into

the

tab

rack.

Tab

lever

binding

on

the

margin

rack.

Bind in

the tab

lever.

Improper

latch

stop

adjustment

I

allowing

excessive

clearance

between

tab

lever

and

tab

rack.

Friction

governor

too

tight.

Insufficient

carriage

tension.

Tab stop

not

completely

set.

See

that

the

operator

is

not

beating

the

tabular

operation.

This

would

appear

as

tabulating

short

by

less

than

a full

space.

Rebound

check

lever

may

be

too

low

and

passing

under

the

tab

stop

or

may

have

excessive

clear-

ance

with

the

tab

stop.

Bouncing

or

maladjusted

contacts.

Bind in

carriage.

TABULATES

EXTRA

SPACES

Tab

lever

not

getting

sufficient

bite

on

the

tab

stop.

Friction

governor

too

loose.

Excessive

carriage

tension.

Tab stop improperly

set.

CARRIAGE

LOCKING

Tab rebound

check

lever

holding

tab

stop

too

tightly.

Improper

latch

adjustment

not

allowing

tab

lever

to

unlatch.

Friction

governor

too

tight

not

allowing

the

tab

I

ever

to

knock

off.

Rebound

check

lever

too

high,

catching

and

holding

the

tab

lever

out.

BACK

SPACE

FAILS TO OPERATE

Bind in

cam.

Improper

cam

adjustment.

Bind in

linkage.

Broken,

bent

or

improperly

adjusted

guide

lug.

Fractured

cam

or

links.

Broken

escapement

spring

or

corner

bell

crank

spring.

Final

stop

adjusted

too

close.

Adjust

height

of

back

space

pawl.

I

nterlock

binding

or

interfering

with

back

space

pawl.

Binding

keybutton.

Glazed

power

roll

,;

BACKS TWO SPACES

Cam

repeats.

Excessive

play

in

linkage.

Improper final stop

adjustment.

Improper

guide

lug

adjustment.

INTERMITTENT

FAILURE

Lack

of

lubrication

on

back

space

pawl.

Improper

cam

adjustment.

Fractured

cam.

Excessive

play

in

linkage.

Improper final stop

adjustment.

Improper

guide

lug

adjustment.

Adjust

height

of

back

space

pawl.

3.8

SPACE

BAR

FAI

LS

TO OPERATE

Check

cam

adjustment.

Bind in

cam.

Space

bar

binding

on

cover.

Improper

stop

bracket

adjustment.

Improper

cam

link

adjustment.

Spring

on

escapement

lever

plate

loose

or

stretched.

Bind

or

maladjusted

plunger

-

(critical).

Plunger

must

be

lined

up

directly

over

the

hole

in

the

top

of

the

solenoid

to

eliminate

possible

binds.

Plunger

bottoming

in

solenoid.

REPEATING

Faulty

cam

(do

not

confuse

with

need

for

stop

bracket

or

cam

Iink

adjustment).

Stop

bracket

adjustment

too

low.

Improper

cam

link

ad

j

ustment.

Operator

may

be

operating

the

space

bar

twice.

ERROR

TYPEOUT -CHECK

LITES

Selector

Contacts

maladjusted.

Ribbon I

ift

operating

Iink

shorting

contacts.

Worn

letter

cam

pivot.

Loose

contact

wires

or

short

be1ween

pins.

Binding

typebar.

Broken

keyboard

contacts.

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.

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.

1)

Check

transfer to

MDR

2) If

Op

37

check

set

of

MBR

from

zone

translator

3)

Check

sync lamp timing and

duration

(Note

2) (Page

3.

11)

4) Refer to

Section

IV

(Core Storage)

(Page

4.2)

Scoping

Procedures

Notes:

1.

Read Photo Diode Adjustment Procedure

Read

Checks

1621

MBR

Checks

READ

Checks

MBR

and

READ

Checks

1)

Check

Photo Diode outputs

(Note

1)

2)

Check

Sync

Lamp

Timing and

Duration

(Note

2) (Page

3.

11)

3)

Check

Voltage

Taps on

1621

power

transformer to insure

they

conform to

the

tap settings

on

the

1620 transformers (208V

or

230VAC)

4)

Check

Read Window to insure

that

it

is

free

of

dust and

that

the

window mask

is

clear

of

photo

diode

Iight

path.

(False Read

Check)

Check

VRC

Circuit)

G,

and A4A05B,

D,

H, G on

02.83.50.1.

Before

the

following

diode

adjustments

are

made,

clean

the

read head

area

to remove a

II

dust from

the read

window.

Make

certain

that

the

+12 and

-12v

power supplies

are

adjusted

to

the

nominal

values

given

on

the

1620

voltage

specification

chart.

4)

Select

a

diode

that

has

an

output

that

is

near

to the

average

output

of

all

diodes

and

use

it

as

a

reference

or

base for Steps 5

and

6.

For

example,

see

Figure

1.

Channel

Scope Point

Voltage

Reading

1 A4A04 B

-lO.Ov

1)

Center

diode

potentiometers

1 through

8.

2) Set read lamp

potentiometer

for minimum

intensity.

3) Record

diode

output

with

no

tape

in

machine.

Scope

channels

1 through 8

at

A4A04B,

D,

H.

3.

10

2 A4A04 D -

8.0v*

3 A4A04 H -

9.2v

4 A4A04 G -

6.4v

5 A4A05 B

-11.3v

6 A4A05 D -

2.2v**

7 A4A05 H -

9.8v

8 A4A05 G

-1O.4v

-67.3

8.4v

Ave

-'2..)67.3

*Use this

diode

as the

reference

diode because

it

is

closest to the

calculated

average.

**

Th

is

diode

may need to

be

rotated,

the

mask

may

be

dirty or

out

of

adjustment,

the

gasket

may be

out

of

place

or

the

diode

may need to

be

replaced if

it

cannot

be

brought to

specified

levels.

5) With no

tape

in the machine, scope the

refer-

ence

diode

selected

in Step 4 and

adjust

the

.read lamp

potentiometer

until the

diode

output

is

-lOv.

Ideally,

the potential on the read

lamp should

not

exceed

llv.

6) Scope the remaining diodes and

adjust

the

individual read

diode

sensitivity

potentio-

meters for a

-lO.Ov

output

at

each

diode.

This

is

a starting

point

for the following

adjustments:

If

-lOv

cannot

be

obtained,

it

may be

nec-

essary to

change

the

read lamp

potentiometer

adjustment, keeping

in

mind the ideal

poten-

tial for the lamp. If the read lamp

potentio-

meter

is

re-adjusted,

the diode outputs should

be

re-checked

and the

diode

potentiometers

re-adjusted

if necessary.

7)

(a) Punch up a length

of

tape with 1,

2,

4,

8,

C,

0,

X,

EL,

etc.,

in

consecutive

positions.

This

can

be

done by inserting

a read

alphameric

instruction with the

typewriter

designated as the input

device

(3700501

00100).

RELEASE

and

START.

Depress

the

sh

ift

key

and type

1,

2,

4,

8,

spare

bar,

0,

-,

+.

Nowsetupa

program loop to

write

alphamerically on

the punch (39 00500 00200 49 00000

00000).

RELEASE

and

START.

The

paper

tape

punch should now be punching the

desired

pattern.

Form

the punched

tape

into a loop and

place

on the read

head.

A good spl

ice

can

be

made by

cutting

the

tape

on

an

angle,

about

450; holding the

ends

of

the

tape,

with

Channell

toward

you,

overlap

tape

end in

LEFT

hand

OVER

tape

end in RIGHT hand by

1/16"

to

1/8".

Glue

in this

position,

with feed holes

aligned,

using a quick setting

glue

such

as I

BM

tape

muci

lage,

Part #221020.

(b)

Set

1621

switch for strip mode.

3.

11

(c) Depress NON-PROCESS RUNOU T.

The

loop should now

be

running

over

the read

head.

(d) Measure the

peak-to-peak

voltage

swing

at

the points given in Step

3.

The

diode

swing

is

a result

of

the

change

in

light

when reading through

tape

(positive

level) to a light through a

code

hole

(negative

level) and

is

a function

of

diode

sensitivity and

tape

transparency.

The

diode

potentiometers will

adjust

the

plus and minus levels

up

or

down simul-

taneously.

r-

(1)

The

peak-to-peak

voltage

swing must

be

at

least

14.0

volts.

If

a

diode

fails to meet the minimum

14.0

volts

swing with the power supplies

at

their

nominal

values,

and rotation

of

the

diode does not increase the

sensitivity thereby increasing the

swing,

replace

the

diode.

(2) For diodes with

peak-to-peak

volt-

ages

between

14.0

volts and

22.0

volts,

center

the

voltage

swing

about

-1.0

volt

reference with the

diode

potentiometer.

For

example,

a

diode

with a minimum swing of

14.0

volts would

be

set

to +6v and

-8

.Ov. See Figure

1.

+10.0

-"..-

+

5.5

"..

/

V -

1.0

_____

-

6.5

~

______

~~

__

~~

_______________

-12.0

Flattened Curve Indicates

Saturation (Above

-11.

9v)

Proper Adjustment For

Diodes With

Peak-To-

Peak Swing

From

14.0v

To

22.Ov

Figure

1.

swing) Diode

Voltage

Adjustment (14 to 22v

(3) For diodes with

peak-to-peak

voltages

greater

than

22.0

volts,

set

the

neg-

ative

peak to

-12.0

volts (just in

saturation).

The

positive

peak

will

be

between

+10.0

and

+12.0v.

See

Figure

2.

(e) Measure

the

+S

ampl

ifier

outputs

at

4A07G,

K, C,

L,

and

4A08G,

K,

C,

and

4A09C.

The + signals must be

at

least

2.0

milli-

seconds in

duration.

(f)

Changes

in

voltage,

temperature,

and

dust on

the

read window

will

cause

the

voltage

level to move up

or

down from

their

initial

values.

An

average

cycl

ic

shift

of

1

volt

is

to

be

expected.

Re-

adjust

any

diode

as

per

7)

(d)

when

the

power supplies

are

adjusted

to

their

nom-

inal

setting

and

anyone

of

the

following

conditions

exist.

See

Figure

3.

(a)

The

positive

level

is

more

negative

than

+5.0

volts.

12.0

__

10.0--------~--------------~~

__

-------

-

1.0

____________

~r_

__

~-------------oo

N.,¢

C"IC"I

-12.0------~...-4.-------

Flattened

Curve

Indicates

Saturation

(About

-11.

9v)

Proper Adjustmen'f For

Diodes

With

Peak-To-

Peak Swing

Greater

Than

22.0v

Figure

2.

Diode

Voltage

Adjustment

(Over

22v

swing

(b)

The

negative

level

is

more

positive

than

7.0

volts.

(c)

The

+S

amplifier

signals

at

points

listed in

7)

(e)

are

less than

2.0

mi

II

iseconds in

duration.

3.12

Figure

3.

Effect

of

Change

in Vol

tage,

Temperature,

and Dust on Read Window

Re-adjust

per

Step 7 if

any

of the

above

conditions

exist.

(c)

Indicates

a

diode

with

less

than

the

minimum

14.0v

swing.

2.

Timhg

Disk

Lamp

and Photo

Diode

The

timing disk lamp must

be

adjusted

so

that

both

of

the

following

conditions

are

met:

1)

The

negative

peak

of

the

diode

measured

at

A4A06C must

be

set

to

-12

volts (just in

sat-

uration)•

2)

The

trailing

edge

of

the

sync pulse must

be

in

the

center

of

the

code

pulse

within

.5m

sec

for

all

channels.

Whenever

the

lamp assembly

is

shifted to

obtain

the

correct

timing,

a

change

in

diode

output

wi"

be noted

because

this

adjustment

also

affects

vertical/horizontal

positioning

of

the

light

source

relative

to

the

diode.

More

or

less I

ight

reaching

the

diode

alters

the

sync

diode

output

which

in

turn

causes

a

wider

or narrower sync

pulse.

Since

timing

is

arrived

at

using

the

traiIing

edge

of

the

sync

pulse,

the

diode

output

and

timing adjustments

are

interacting.

To

satisfy

conditions

1

and

2 as

previously

stated,

the

combined adjustments of

the sync lamp

potentiometer,

lamp,

socket,

timing disk

diode

potentiometer,

and/or

the

complete

lamp

block

assembly may

be

required.

ADJUSTMENT

The lIanded

ll

output

of

tape

Channels

1,

2,

3,

6 and

7

can

be

used to

check

the

sync pu Ise timing as

follows:

1.

Punch up a length

of

tape

with

G,

EL,

G,

EL,

etc.,

in

consecutive

positions.

This

can

be

done

by inserting a read

alphameric

instruction with

the

typewriter

designated

as

the

input

device.

INSERT. Type

3700501

00100,

3900501

00200,

49

00012.

RELEASE

START. Type

G,

:j:.

RELEASE.

START.

The

paper

tape

punch shou

Id

now

be

punching

the

desired

pattern.

Form

the

punched

tape

into a loop and

place

on

the

read

head.

2.

Tie D1D14F and D1D14G to ground (system

dia-

gram

01.80.30.1).

The

eight

input AND

will

now

be

satisfied

when

reading a

IIG

II

character.

(Tape

channels

1,

2,

3,

6,

and

7;

and

channels

4

and

5

tied

to

ground).

The

tape

pattern

with

alternate

IIG

II

and

IIELII

punches

is

used to

obtain

a

data

signal

every

other

character.

3.

Set

up a program loop to read

tape

as follows:

INSERT; Type

3700501

00300,

4900000.

RELEASE;

START;

The

reader

should now

be

run-

ning

the

loop

of

tape.

4.

Set

scope

trigger

mode to

external

minus.

5.

Sync

scope

on lIanded

ll

output

at

D1D14E on

01.80.30.1.

6.

Scope D1D

14E

and p

lace

the

center

of

the

-S

waveform in

the

center

of

the

scope

face.

The

-$

lIanded

ll

output

must

be

at

least 2 milliseconds

in

duration.

Failure

to

meet

this requirement

ind

icates

an

improperly a Iigned read mask.

7.

A

time/div.

setting

of

approximately

509

sec/div.

will

spread

the

-S

output

waveform across

the

scope

face.

8.

Scope

the

sync

diode

output

at

A4A06C on

02.83.50.1.

(a) Set the timing lamp

potentiometer

for

lOv

across

the

lamp.

(b) Adjust the timing disk

diode

potentiometer

for

a

negative

peak

of

-10v

on the timing signal

(adjust the timing lamp if

the

potentiometer

Iimit

is

reached).

(c) Loosen the two lamp assembly holding screws

and

adjust

the assembly for a maximum

neg-

ative

peak.

Make sure

that

the

top of

the

timing lamp

is

not

touching

the

drive

shaft.

(d)

Re-adjust

the

timing disk

diode

potentiometer

to

set

the

negative

peak

to -12v on the

timing signal (just in

saturation).

9.

Scope

the

type sync

output

pulse

at

A4A06A and

adjust

the

lamp assembly so

that

the

fall

of

the

sync pulse

(+S

to

-S)

occurs in the

center

of

the

lIanded

li

output

waveform

within

0.5

milliseconds

(Center

of scope

face

due

to Step

6).

Scope

A4A06A and A4A06C

alternately

to maintain

the

negative

peak

of

the

diode

at

-12v

while

positioning

the

sync.

The

negative

peak

may

be

re-adjusted

to

-12

with

the

timing

diode

potenti-

ometer

to

facilitate

this

adjustment.

See Figure

4.

3.

13

Sync Pulse

A4-A06-A

Sum

Of

Bit

Pu

Ises D

1-D

14-E

2.0

Millisecond

Minimum

Bit Pulse (Earl

iest

Fall Time)

Bit Pulse (Latest Rise Time)

Bit Pulse

Difference

In

Duration

Caused

By

Diode

Characteristics

And

Individual

Diode

Potentiometer

Adj

ustment

+S

On

Light

~

1---

--------------------~

~------------------

3.

14

:}

I

2.0

ms

Minimum

Fall Time

Of

Sync Pulse

In

Center

Of

Bit Pulses

Difference

In

l.M:::::~-'::----Ti

me

Caused

By

Skew

Figure

4.

Sync Pulse Timing

IBM 1620 User manual

Popular Desktop manuals by other brands