Radio Shack TRS-80, TRS-80 Model I, 26-1001, 26-1201, 26-1140 Technical Service Data

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MODEL I LEVEL

KEYBOARD,

1\

CPU

BOARD

EXPANSION INTERFACE

SAFETY PRECAUTIONS

Block

Diagram Disassembly General GridTrace

IC Line Logic Miscellaneous Parts

Operating

Location

CPU Board

Pinouts

Definitions

Charts.

List

The llliing of ony

constituteInany

HowardW.Sam, replacement

from manufacturers

& Terminal

information

See

Folder

See page 19

Instructions

Guide

Guides

. .

..

Adjustments

IS,.

available

co,.

& Co. Inc

port. The

fU"~lIhed

of

the

particular

CSCS3-A

Howard

4300

replocement

a

recommendation.

.•asto

numbers

of

to

HowardW$oms

type

West

warrantyorguoranty

'hoe

qualIty

'hes.

parts

01

replacement

Page

6,27

..24,25,26

15,16,17,18

W.

Sams

62nd

Street,

port

herein

and

SUltoblhty

have

been compiled

& Co.. Inc

port

MONITOR

See

Folder

CSCS3-B

PRELIMINARY SERVICE CHECKS

ENCLOSED

INDEX

29

13

19

20

dolu

listed

4 4

of such

by

& Co

P.O.

not

by

the

Photos

Cassette CPU Board 10,11,12,21,22,23 Level

Partial Keyboard 14 Safety Schematics

CPU 2,3,30,31,32,33

Power Schematic Troubleshooting

..

Box 7092,

Reproductionoruse

contentinany

respect

e 1985

"300 West 62nd Str

Pdn'ed

Modification

II

ROM Board

Precautions

Supply

Notes

Inc.

Indianapolis,

monner.

to

the

VI.

of the

How""

W.

sam,

..t,P.O.

in U.S. of

Amefico.

without

is

information

& Co., Inc.

Counter

expre

prohibited.

lox

7092. Indianapolis. Indiana

Indiana

..

permission,

No

contained

poten'

Board 20

85CC14942 DATE 2.85

Page

7,8,9

46206

U.S.A.

of

editorial

Iiobilityi,os.Jumed

herein.

0(

<16206

14

19

5,28

piC1oriol

U.S.A.

9

with

~

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.....

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COMPUTCR'C"CTS"'

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' M

PRELIMINARY SERVICE CHECKS

RADIO SHACK

....O..D..

E_L_I_L..EV_E_L..I..I_

TRS·SO

This data provides the user designed for malfunctions.

Check all correct

o

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w

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0

-0

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a:

ROM

SELECT SHUNT

Rom Select Shunt

M Level I

.

CJ)

()

CJ)

or

LevelIIBasic ROMs are installed. Use the follow-

ing charttodetermine which pins are shunted.

Z3 PINS BASIC BASIC

(Z3)

CPU

(Z3)

is set up in accordancetowhether

LEVELl

()

1-16 2-15 3-14 4-13

5-12 6-11 7-10 8-9

Open Shunted Shunted Open Shunted 2-15 Shunted Shunted 3-14 Open Shunted 4-13 Shunted Shunted Shunted Open Shunted 7-10

with

quick

isolation

interconnecting

hookup

before making service checks.

Disconnect all external peripherals from systemtoeliminate possible external

a time-saving service

and repair of

cables

for

good

computer

connections

the

malfunctions.

ReplacementorrepairofPower Supplies, Board, Expansion Interface Board and connectors

may be necessary

after

Monitor

the

malfunction

been isolated.

MISCELLANEOUS ADJUSTMENTS

AND KEYBOARD

LEVEL

II

Shunted

Shunted 5-12

RAM SELECT SHUNT

RAM Select Shunt

amount of RAM memory (4K or 16K) installed on

the

Use

following

shunted.

271

PINS

1-16

6-11

8-9 Open

tool

system

and

computer

CPU

(Main)

Boards or

has

(Z71)

CPU

AND KEYBOARD

(Z71)

is set up in accordancetothe

charttodetermine which pins are

4K 16K RAM

RAM

Open Shunted Shunted Open

Open

Shunted Shunted Open Open Shunted Shunted Open Open Open

Open

CPU

Board .

5V

12V AND

NOTE: Perform

Connect the (Z2).

Adjust

Connect the (Z1).

Adjust

12V AND

ADJUSTMENT

12V

inputofaDCvoltmetertopin 3 of Regulator IC the 12.0V

input the5VAdjust

5V

ADJUSTMENT EXPANSION INTERFACE

NOTE: Perform 12V

Connect (Z20).

Connect (Z21).

the

inputofaDCvoltmetertopin 3ofRegulator IC

Adjust

the

inputofaDCvoltmetertopin 3ofRegulator IC

Adjust

the5VAdjust

s

Th.

lI,ting of

constituteinany

Howard W. r.ploc.ment from information furnished to HowardW.$oms & Co ..

manufacturersofthe

CPU

AND KEYBOARD

adjustment

Adjust

before5Vadjustment.

Control (Rl0)

for

11.9V.

of aDCvoltmetertopin 3 of Regulator IC

adjustment

12V

Adjust

I~

lelrTII

any

ovailable

cos.

Saml

& Co

port. The

Control

0 rec:ommeondotion.

.•

Inc

numbers

particular

(R5)

for

5.0V.

before5Vadjustment.

Control

..

(R7)

(R8)

Howard

4300

West

r.plocement

as

to

the

quality

of

the,.

type

of

replocement

for

for 5.0V.

W.

62nd Street, P.O. Box 7092,

port tMreln

warrantyorguaranty

and

pam

hove

11.9V.

Sams & Co., Inc.

does

not

port

Inc

listed.

of such

.. by the

by

suitability

been compiled

HORIZONTAL AND VERTICAL CENTERING KEYBOARD

Type and run the

(O,X): (X,O):

Monitor

SET (127,X) SET (X,47)

tangle on the

10

CLS: FOR X =0 TO

20

IF X>47 THEN

30

SET

40 SET

following

40

Basic programtoproduce a rec-

screen:

127

50 NEXT X 60 GOTO 60

Adjust

the Horizontal Center Control (R20) and Vertical

Center Control

(R21)tocenter the rectangle on the

screen.

Indianapolis,

R_oductlon

conl..,t,

r.sp«'

~

4300 W.., 62nd

PrintedInU.S.of"memo.

11185

0.-

.....

In

to Howanl

without

ony

manner.

the u

..

of the Infarmotlon contolned

W.

Sam.

St,..t. P.O.

i.

Indiana

_p'."

prohibited. No pot..... liobUlty

& Co.,

Inc:.

lax

7092. Indianapolis. Indiana

46206 U.S.A.

pennl..lon.01edltoriol

"-<eln.

85CC14942

I.

auumed

~

DATE

0.-

CPU

picto.-lol

with

U.S.A.

2-85

AND

Monitor

CD

PRELIMINARY SERVICE CHECKS (Continued)

SERVICE CHECKS

SEE INTERCONNECTING DIAGRAM AND PHOTOS CIRCLES WITH THOSE FORMED.

POWER SUPPLY

(A)

Disconnect the from tween pin 1 and pin 3 and 23.6V between pin 2 and pin 4 voltages are missing, replace the Power Supply Module.

(B)

Check measurement is ment

(CPU

BOARD)

Connector

for

of

CPU

J1A and check

of

the Power Supply Plug (P1A). If

5.0V at pin 3ofRegulator IC not

the5VAdjust

IN

THE FOLLOWING DATA FOR SERVICE CHECKS TO

Power Supply Module(PT1)

correct, check the adjust-

Control

for

18.5VAC be-

(R5).

the

(Z1).Ifthe

CD

® MONITOR DEAD

® CASSETTE PORT INOPERATIVE

TO

MATCH THE NUMBERINTHE

BE

VIDEO DISPLAY UNSTABLE

(A)

Check the Coil (L4) and Vertical Hold Control (R13B) located on the rear of the Monitor.

(A)

Check Fuses Monitor.

adjustmentofthe Horizontal Hold

F101

and F103 located inside the

PER-

(C) Check

COMPUTER DOES NOT COME

(A)

(B)

(C) Check RAM ICs Z13 thru Z20 by

KEYBOARD

(A)

(B)

(C)

for

11.9V at pin 3 of Regulator IC

the

measurement is

justmentofthe 12V

Seeifthe Select see "ROM Select Shunt Z3" laneous Adjustments.

Check Regulator IC (Z40)bysubstitution.

If only one key is

contacts

key key is contacts tacts

If several keys are not working, check the ribbon cable between Keyboard and possible

If

wrong character appears on the screen when a key is pressed. Check Character Generator IC

ROM

Shunts

with

still

defective, check

and solder

with

an ohm meter.

open

not

correct, check the ad-

Adjust

Control (R10).

UP

PROPERLY

Select

Shunts

(Z71)

have been set up properly,

(Z1)

not

working properly, clean the

a spray

joints.

circuits.

(Z29)bysubstitution.

sectionofMiscel-

and

Microprocessor

contact

for

breaks at

Check the key con-

(Z3)

substitution.

cleaner. If the

CPU

(Z2).

and RAM

the

key

board

Monitor

IC

for

If

(A)

Check the Cassette cables for looseorbroken wires and also check Board and sion Interface Board

(B)

If the Cassette the Computer Off. Use for

an open

of

RelayK1to Relay contacts are shorted.

POWER SUPPLY (EXPANSION INTERFACE)

(A)

Disconnect the Expansion Interface Power SupIy Module (PT1) from

19.7VAC between pin 1 and pin 3 and 23.6V between pin 2 and pin 4ofthe Power Supply Plug Power Supply Module.

(B)

Check the measurement is incorrect, check the adjustment

(C) Check

the measurement is incorrect, check the adjustmentofthe5VAdjust

DISK DRIVE PORT INOPERATIVE (EXPANSION INTERFACE)

Connectors

motor

circuit

the center pin at the

K1.

If the pins are shorted,

are

sticking

(P9).

If the voltages are

for

11.9V at pin 3ofRegulator IC

of

the 12V

for

5.0V at pin 3ofRegulator IC

Connector

J6, J7 and J8 on Expan-

for

good connections.

will not

an

ohm

from the center pin at one end

or Diodes CR9 and CR10

Connector

missing,

Adjust

Control

J3 on

stop

running, turn

metertocheck

other

either

Relay

J9 and check

replace the

(R7).

(R8).

end

(Z20).

(Z21).

CPU

of

K1

for

DC

If

@ NO VIDEO ON MONITOR

(A)

Check the video cable

Connector

Video

(B)

Check the (R102) and Brightness Control (R103) located on the

Monitor.

VIDEO DISPLAY NOT CENTERED

(A)

Check the

the

(R20)

CPU

Control on Centering" justments.

II

(J2)

adjustmentofthe

adjustmentofthe Horizontal Center

and Vertical Center Control

Board,

section

for

broken wires and the

for

good

connection.

Contrast

ON

MONITOR

see"

Horizontal and Vertical

of

Miscellaneous

Control

(R21)

Ad-

(A)

Check Disk Drive cables

wires and Clean Connector J5 cleaner.

(B)

Check Disk

LINE PRINTER PORT INOPERATIVE (EXPANSION INTERFACE)

(A)

Check the Line Printer cable for loose or broken

wires and Connector J4

Clean

cleaner.

ConnectorJ5for

ControllerIC(Z42)bysubstitution.

ConnectorJ4contacts

for

loose or broken

good

contacts

for

good connections.

connections.

withacontact

MONITOR

PRELIMINARY SERVICE CHECKS (Continued)

@

HORI1

@

I«llD

VERT

HCl.D

CHASSIS

F103

0

]A

SIZE

VERT

rnD

Q

_

®

F~'

0

PRELIMINARY SERVICE CHECKS (Continued)

CASSETTE

L

Y

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CASSETTE

2 I

34

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DISK

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~

8 L

t:.:

PRINTER

PORT

I20VAC

8

....

~-~

'V'----.,

MONITOR

P I CPU

POWER

SlI'flt

y

@

MAIN

BOARD

0-----

r-----~

LEVEL

IT

ROM

CASSETTE

HOOIF

lCATlOH

COUOfTER

!IOARD

BOARD

@

HOR~

CENTER

R21

{

VERT

CENTER

MON

ITORVIDEO

BOARD

19.7VAC

CPU

EXPANSION

J1

INTERFACE

40

BOARD

8 RIO

@

Rf6lLAT~

5.~

@)

EJ

CJ@

Rf6tl.AT~

m

/6

11.9V

BBBBBBBB

"Y"

BOARD

FWl

®

lCa

2

HI~

@)

Z40

SU'"FERED

INTERFACE

39

40

'--------I

J3

IllS

PORT

40

52

RESET

INTERCONNECTING DIAGRAM

X

Z33

FWl

SHMTS

KEYBOARD

INTERCONNECTING DIAGRAM

III

PRELIMINARY SERVICE CHECKS (Continued)

GENERAL OPERATING INSTRUCTIONS

POWERUP(COMPUTER ONLY)

words

Turn On the Computer. The

pear on the word" Monitor

POWER

1.

Turn On the Expansion ·Interface.

2.

TurnOnthe Disk Drives (Terminal Drive 26·1164A, first) and then any

3.

Put a into will of screen along prompt

NOTE: Disk Drive, puter. A screen. Press Enter key and the pear followed by a now in Basic mode.

RESET

Press the Break key and the Reset the Computer) to reset the Drives are attached, mation This

DISK OPERATING SYSTEM (DOS)

Type DIR and press the Enter key programs and the contains

list

To load a program from a gram and press the Enter key. Use a of the Disk Drive

If no

NOTE: Computerisin the Disk Basic mode.

To get back to the DOS from Disk Basic mode, type

Monitor

READY" and a

screen. The

UP

SEQUENCE (WHEN USING DISK DRIVE)

diskette

Disk DriveO.Turn On theComputer. The

automatically

the

Disk

character.

If

into

will

reboot

that

numberofthe Disk Drive

the

programsondiskette

number

Basic

screen. Press the Enter key once. The

prompt

Computerisnow

other

peripherals.

(containing

boot

up from Disk DriveO.The version

Operating System

with

the words "DOS READY" and a

an Expansion

hold

double"

Disk Drive 0 and press

the

are on the

information

which

is given, the

program

Interface

down

Break key when

MEM SIZE?"

prompt

ComputertoBasic mode.IfDisk

insertadiskette

Computer

diskette

desired. Example: Type DIR:2to

in Disk Drive

diskette,

contains

system

will

not load from

nMEM SIZE?"

character

DOS, Disk

character. The

from Disk Drive

will

in Basic mode.

Operating

will

appear on the

unit

is used

turning

will

appear on

word"

READY"

button

(on

containing

only

the Reset

to

displayadirectory

in Disk DriveO.Type DIR :

holding

the

2.

type the name of the pro-

colon

and the

the programtobe loaded_

will

assume

diskette

will

appear on the

System)

Computer

Monitor

without

On Com·

Monitor

will

Computer

right

rear

DOS infor-

button.

O.

diskette

which

number

Disk Drive

unless

CMD"S"

willbelost

ap·

DISK BASIC

To load Disk Basic sert a DOS key and DOS, type in memory

To load a program from a gram name enclosed in

load from a Disk Drive the

ample: LOAD

To save a program SAVE and the program name in

key. To save a program

a

than Disk Drive0,add a the end Disk Drive

ap·

is

FORMATIINGADISKETIE

NOTE: This procedure System diskette

of

containing2or to

A blank saving data. To diskette

DOS

the Enter key.

of

blank

tions

CASSETIE

To load a program from tape, type CLOAD (with

the program name enclosed in quotes), play when program has been loaded.

and press the Enter key. Any program in

when leaving Basic

diskette

diskette)

follow

CMD"S"

will

Disk

Drive

of

the program name. Example: SAVE

1.

sections

thus

format a

diskette

with

diskette)

diskette

on the

Monitor

OPERATION

mode

and press the Enter key. Prompt

O.

To save a program

the

the program name enclosed in quotes), record mode and press the Enter key. A dicate

when

writing

modebyusing

into

the Computer,

containing

into

Disk Drive0,type BASIC, press the Enter

prompts.

be lost.

number

"SAMS:1"

required for normal

formatted

more Disk Drives.

mustbeformatted formatadiskette,

the

format

into

After into

Disk Basic (usually a partofthe

Togofrom Disk Basic

and press the Enter key. Any program

diskette,

quotes

other

than Drive0,add a

at the endofthe program name. Ex-

for Disk Drive

ontoadiskette

colon

and the Disk Drive

does

must

containing

program on it (usually partofthe

the Disk Drive, type FORMAT and press

the program has been loaded, insert a

the Disk Drive and

screen.

onto

tape, save CSAVE (withorwithout

has been completed.

boot

type LOAD and the pro-

and press the Enter key. To

in a Disk Drive, type

quotes

in a Disk Drive

not

copy Disk Operating

disk

be used

Use"

DOS

information.

before it can be used

bootupon DOS, insert a

"CMD"S".

up on DOS. In-

1.

and press the

"SAMS:1"

operations. A

only

with

Back-up"

follow

put

the Recorder in

will

put

the Recorder in

prompt

memory

mode

to

colon

and

Enter other

number

the instruc-

or

for

systems function

for

without

indicate

will

at

in-

IV

PRELIMINARY SERVICE CHECKS (Continued)

@

CE

HORll

R20

{

CR10

TER

CR9

K1

®

CASSErE

J3

Af1A\

@

V

DEO

J2

f3C\

~

POWtRSWTCH

Z29

J1

POWER

Sl

@

®

r

..

@

®

@

SELECT

ROM

SHU

Z3

TS

@

RAM

SELECT

Z71

SHU

TS

Z40

KEYBOARD

@

®

CABLE

CPU BOARD

VIII

CPU BOARD

V

PRELIMINARY SERVICE CHECKS (Continued)

@

..

PRELIMINARY SERVICE CHECKS (Continued)

G~0

OS

DREpaR

J5

LINE PRI

TER

12V

ADJ

R7--

@ 120V

{

PI

Z20

5V

AoJ

~~_j~RT

3

BUFFERED

INTERFACE BUS PORT

~~-J3

@

:tl

3:>

52

0

m(f)

r-z

->

r-(')

m~

<0004

~:tl

_(f)

-eo

o

@{

PI

R8

~

OV

3

Z21-....JIi==

POWER

J9

EXPANSION INTERFACE BOARD VI

EXPANSION INTERFACE BOARD

VII

PRELIMINARY SERVICE CHECKS (Continued)

@

CE

HORll

R20

{

CR10

TER

CR9

K1

®

CASSErE

J3

Af1A\

@

V

DEO

J2

f3C\

~

POWtRSWTCH

Z29

J1

POWER

Sl

@

®

r

..

@

®

@

SELECT

ROM

SHU

Z3

TS

@

RAM

SELECT

Z71

SHU

TS

Z40

KEYBOARD

@

®

CABLE

CPU BOARD

VIII

CPU BOARD

V

ENVIRONMENT

PRELIMINARY SERVICE CHECKS (Continued)

PREVENTATIVE MAINTENANCE

Computers though maintain Monitor,

ELECTRICAL POWER

Variations in the line voltage can power non-interruptable

KEYBOARD

liquids power printed tact

DISK DRIVES

Clean the read/write headsofthe Disk Drives about ing kit.

Handle of

alignment.

Store on the back of

PRINTERS

Carefully vacuum the Printer regUlarly. Wipe surface areas clean using a The oil

perform best in a clean, cool area

home

Computers

a smoke-free area around the Computer. Do

Printer,orother

line

not

used by appliancesorother

spilled

into

outlet.

Then,ifcircuitryorcontacts

circuit

cleaner and lint-free wipers on accessible

disksintheir

board

carefullytopreserve proper

If the

disk

will

collect

are not affected by

power

devices.

affect

power

supply

may be neededtocure the problem. Do

the Keyboard can ruin it.

with

distilled

disk

drive

protective

abrasive

water and let it dry. Use a

disk

must

be transported, place an

covers and never

covers.

grit

and

dust.

the Computer. Trytoavoid these

heavy

head alignment. A sudden bumporjolttothe

The

thatisbelow80degrees Fahrenheit and freeofdust cigarette

Immediately

are

smoke as

not

block

current

demand devices. A power-surge protector, power-line

afteraspill

contaminated,

connectors

onceamonthorafter

touch

dust

will

the

disk

act

colton

and

old

as a blanket.

muchascommercial

cabinet ventsofanyofthe

occurs,

disassemble

swabtoclean between the keys. Use a non-abrasive con-

contacts.

diskinslot

surface. Observe the

Computers

fluctuationsbyusinganAC receptacle that is on a

not

switch

powerOnand

disconnect

the Keyboard and

100

hours

usage. Use

Disk

and

close

door

disk

handling precautions

light

all-purpose cleaner. Do

This

can cause

and smoke particles. Even

are affected,itis

Computer

the

Computer

carefully

only

Drives can

during

componentstooverheat and fail.

system; Computer,

Off

frequently.

power plug from

rinse the Keyboard

an approved head clean-

knock

the

transport.

not

oil the machine.

belter

conditioner,

disk

head

usually

found

AC

out

to

or

::z:J

3:>

O~

cO

men

r""::I:

->

r""O

m"

<~

~::z:J

_en

-cio

o

STATIC ELECTRICITY

Static

electricity

and materials, and maintain good

MONITOR

Use an chassis at preserve the glare-reduction feature.

high

isolation

(chassis

brightness

discharge

transformer

connectedtoone sideofthe AC line). The faceofthe

level except when pattern is being changed periodically. Use

can

affect

with

the Computer. In ordertominimize

humidity

any

in the

Monitor

Computer

that

does

environment.

not

come

the

possibility,

as partofthe system

Monitor

should

caution

never be

use

anti-static

since

leftonfor

when cleaning anti-glare screens,

some

mats, sprays,

Monitors

long

periodsoftime

tools

use a HOT

to

IX

MONITOR

PRELIMINARY SERVICE CHECKS (Continued)

@

HORI1

I«llD

@

VERT

HCl.D

CHASSIS

F103

0

]A

SIZE

VERT

rnD

Q

_

®

F~'

0

PRELIMINARY SERVICE CHECKS (Continued)

CASSETTE

L

Y

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2 I

34

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PRELIMINARY SERVICE CHECKS (Continued)

TEST EQUIPMENT AND TOOLS

CPU

BOARD

ITEM

CR9 4800026 CR10 4800026 K1 PT1 R5 R10

R20

R21

Z1 Z2 Z3 Z13 3108009

thru

Z20

Z29

Z40

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TEST EQUIPMENT

Digital Voll/Ohm Meter logic

Probe

PARTS LIST

DESCRIPTION

Diode, 1N982A Diode, 1N982A Relay,

Motor

Control, Power Supply Module Control,5VAdjust, 1000 Ohms Control, 12V Adjust, 1000 Ohms Control, Horizontal Center, 100K Ohms Control, Vertical Center,

100K Ohms IC, Regulator, MC1723CP IC, Regulator, MC1723CP Shunt,

ROM

Select IC, RAM, MB8116E IC, RAM,

IC, Character Generator, 8046670 IC, Character Generator, MCM6670 IC, Microprocessor, IC, Microprocessor, Z80 Shunt, RAM Select

5V

D780C·1

TOOLS

Phillips Screwdriver

Small Screwdriver

Contact Cleaner low

Voltage Soldering Iron

Desoldering Equipment

AND

DESCRIPTION

EXPANSION INTERFACE BOARD

ITEM

PT1 R7

R8

Z20

Z21 Z42

PART NO.

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4750019

31ססoo1

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ITEM

F101 F103 L4 R13B

R102

R103

PART NO.

426973 99328

141017 141022

140980 140711

DESCRIPTION Power Supply Module

Control, 1000 Ohms Control,5VAdjust, 1000 Ohms

IC, IC, Regulator, MC1723CP IC, Disk Controller, FD1771

DESCRIPTION Fuse, 1A @250V, Fast

Fuse, 5A @250V, Fast Coil Horizontal Hold Control, Vertical Hold,

200K Ohms Control, Contrast, 500 Ohms Control, Brightness, 200K Ohms

12V

Adjust,

Regulator, MC1723CP

B-{)1

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DISASSEMBLY INSTRUCTIONS

CABINET REMOVAL

Remove six screws from cabinet bottom. Remove cabinet top and ponents are now accessible for service.

CABINET REMOVAL EXPANSION INTERFACE

Remove six screws from cabinet bottom. Remove cabinet bottom

service.

bottom

from unit. All components are now accessible for

CPU

AND KEYBOARD

from Keyboard and

CPU

Board. All com-

CABINET REMOVAL MONITOR

Remove five screws holding cabinet back and remove back. All components are now accessible for service.

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1985

SEE LINE DEFINITIONS ON PAGE 19

J

GENERAL OPERATING INSTRUCTIONS

POWERUP(COMPUTER ONLY)

"MEM

Turn On the Computer. The words pear on the word "READY" and a Monitor

POWER

1.

Turn On the Expansion Interface.

2.

Turn On the Disk Drives (Terminal Drive 26·1164A, first) and then any

3.

Put a into will of screen along prompt

NOTE: If an Expansion Interface Disk Drive, hold puter. A screen. Press Enter key and the pear now in Basic mode.

RESET

Press the Computer)toreset Drives are attached, insert a mation This

DISK OPERATING SYSTEM (DOS)

Type DIR and press the Enter key

programs and the contains

list

programs on

To load a program from a diskette, type the nameofthe pro-

gram and press the Enter key. Use a of the Disk Drive

no

If

NOTE: Basic program

Computer

To get back to the DOS from Disk Basic mode, type

Monitor

screen. The

UP

SEQUENCE (WHEN USING DISK DRIVE)

diskette

Disk DriveO.Turn On the Computer. The

automatically

the Disk Operating System will appear on the

character.

followed

the

Break key and the Reset

into

will

reboot the

that

numberofthe

the

number is given, the system

is in the Disk Basic mode.

screen. Press the Enter key once. The

prompt

Computerisnow

other

(containing DOS, Disk Operating System)

boot

with

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double

"MEM

by a

Disk Drive 0 and press

Computer

are on the

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information

diskette

which

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character

peripherals.

up from Disk DriveO.The version

the words "DOS READY" and a

Break key when

SIZE?"

prompt

character. The

the

ComputertoBasic mode. If Disk

diskette

from Disk Drive

to

diskette

contains

in Disk DriveO.Type

holding

desired. Example: Type DIR:2to

in Disk Drive

the programtobe loaded.

will

not load

from

SIZE?"

will

in Basic mode.

unit

is used

turning

will

appear on

word"

READY" will ap-

button

(on

containing

only

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display a

the

2.

colon

and the number

assume Disk Drive

diskette

will

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without

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right

rear

DOS infor-

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directory

diskette

DIR

which

unless the

CMD"S" willbelost

DISK BASIC

To load Disk Basic

sert a DOS diskette) key and DOS, type in memory

To load a program from a diskette, type LOAD and the program name enclosed in load from a Disk Drive the Disk Drive number at the end ample: LOAD "SAMS:1"

To save a program SAVE and the program name in key. To save a program

a

than Disk Drive 0, add a colon and the Disk Drive number at the end Disk Drive

is

FORMATIING

NOTE: This procedure does System diskette

of

containing

to

A blank

saving data. To format a diskette,

diskette

DOS diskette) the Enter key.

of

blank

:

tions

CASSETIE OPERATION

To load a program from tape, type CLOAD (with or the program name enclosed in quotes), play mode and press the Enter key. Prompt when program has been loaded.

and press the Enter key. Any program in memory

when leaving Basic mode by using

into

diskette

formatadiskette

diskette

on the

containing

into

follow

prompts. To go

CMD"S"

will

be lost.

of

the program name. Example: SAVE "SAMS:1"

1_

A DISKETIE

sections

thus

formatted

2 or more Disk Drives.

diskette

with

the format program onit(usually partofthe

into

After

into

Monitor

the Computer,

Disk Drive0,type BASIC, press the Enter

required

must

Disk Basic (usually a partofthe

and press the Enter key. Any program

quotes

other

than Drive 0, add a

for

Disk Drive

ontoadiskette

for

must

containing

be formatted beforeitcan be used

the Disk Drive, type FORMAT and press

the program has been loaded, insert a

the Disk Drive and

screen.

boot

up on DOS. In·

from

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and press

of

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not

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be used

DOS

the

the program name.

1.

in a Disk Drive, type

and press the

in a Disk Drive

copy

Disk Operating

disk

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Use"

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information.

boot

up on DOS, insert a

follow

put

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O.

onto

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when

writing

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prompt

has been completed.

"CMD"S".

to

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colon

and

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Enter other

for

operations. A

with

systems function

for

the

instruc·

without

will

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will

in-

DISASSEMBLY INSTRUCTIONS

CABINET REMOVAL

six

screws

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and

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bottom

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from

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for

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27

POWER SUPPLY

TROUBLESHOOTING

CPU

CLOCK AND DIVIDER

Computer is dead. Disconnect the PowerSupply the

CPU of nector connections at Connector J1A and check for open power cord. If the correct voltages are present, reconnect the Power Supplytothe puter. Check for 5.0V at pin 3ofRegulatorIC(Z1), pin 3ofRegulatorIC(Z2) Diode CR2. If all the voltages are missing, check the Power Switch

If 5.0V is missing, check the voltages and components associated

Regulator Drive Transistor (03), Error Amp Transistor (05)

and pins 2 thru7,10,11and13ofICZ1.

rect, check the adjustmentofthe5VAdjust refer to

If the 11.9V is missing, check the voltages and components associated thru7,10,11and 13 of IC the

If the - 5.0V is missing, check Resistor CR2

MICROPROCESSOR (CPU) OPERATION

Check the 1.774MHz

processorIC(Z40). quency, refer to the "CPU Clock and Divider" sectionofthis Troubleshooting guide.

If the waveform is normal, check the operationofthe reset

signal at pin26of

be Low for approximately.1second when the Computer is

turnedOnand then change toand remain High. If the

reading is incorrect, check Capacitor C42, Resistor

check ICs

If the logic reading at pin25ofICZ40

(pins 7 thru10and12thru15ofICZ40) and address lines

(pins 1 thru 5 and30thru40of

When disabled the

and the address lines are Open (No

readings at the

fers, Tri-State Buffer ICs

read Open (No

Z40 is Low, check Resistor

short to ground. The data and address lines fromICZ40 can

be checked by grounding pin25of IC Z40 and checking the

logic

lights

IfICZ40

turnedOnand suddenly stops, pulses appear on data lines

then suddenly stop, check

thru Z20) by

Board. Check

Connector J1A and 23.6V between pin 4 and pin 2ofCon-

J1A. If the voltages are missing, check the cable and

(S1).

with

"Miscellaneous

with

adjustmentofthe

and check for possible short to ground.

Z52

and Z53 by

lights

readings for High on the data lines and

On) on the address lines.

appears to start operating when the computer is

substitution.

for

18.5VAC between pin 1 and pin 3

CPU

Board and turnOnthe Com-

and - 5.0V at the anodeofZener

Regulator

Adjustments".

Regulator

12V

clock

If the waveform is missingoroff

IC Z40. The

logic

inputs

and

On). If the logic reading at pin25of

Output

If the 5.0V is incor-

Output

Transistor (06) and pins 2

Z2.

If the 11.9V is incorrect, check

Adjust

Control

(R19),

waveform at pin 6 of Micro-

logic

reading at pin26should

substitution.

is Low, the data lines

IC Z40)

readings for the data lines are High

outputsofthe address line buf-

(Z22,

R58

ROM

lights

Z38,

Z39 and

and check for a possible

AlBIC(Z1B)RAM ICs

(PT1)

Transistor

Control

(R10).

Zener Diode

will

be disabled.

On). The

Z55),

for

Open (No

from

AC

11.9V at

(04),

(R5),

fre-

logic

R47

and

logic

will also

(Z13

Verify that the for

a frequencyof10.6445MHz at pin 6ofIC clockisoff Capacitor C43. If the clock is not operating, check Crystal Y1,

Capacitor C43, Resistors by

substitution.

The 10.6445MHz (Z56)tosupply to

pin 6ofMicroprocessorIC(Z40).

of

1.774MHz at pin 8ofIC

or

the signal is missing, check the logic reading at pin 6 IC Z56 fora Low.Ifthe Resistor reading at pin 6 is Low, checkICZ56bysubstitution. for pulses at pin 6ofIC Z40. If pulses are missing, check Resistor tion.

VIDEO

No video on the

emitterofthe Video

is normal, check the Video Connector (J2) forgood connection

and check the video cable.

If the waveform is missing at the

check for a video signal at pin 5ofDriverIC(Z41).Ifthe

signal is present at pin 5 ofICZ41, components associated with Transistor 01.Ifsignal is missing at pin5ofIC Z41, check for a video signal at pin 6 IC Z41. If the signal is present, check IC tion. If the signal is missing from pin 6ofIC waveform at pin 3 of IC Z30.

If the waveform is present at pin 3ofIC reading at pin 2ofIC tion. If the Shift

Reg form is 15ofShift pins4,5,10,11 and12ofICZ10. If the waveform and pulses are present, checkICZ10 by

Video display does not operate in the 32 character mode. Type and run the following Basic program and check for pulses at pins 9 and14of

10 OUT 255,8: OUT 255,0: GOTO

IC

If pulses are missing at pin 9ofIC pins 9 and 10ofIC Z25. If pulses are missing from pin 9

IC

Z25, check Tri-State

by

substitution.

check ICs Z36, Z52 and

present at pin 9 and10ofICZ25, check ICZ25 by tion.

If pulses are present at pin 9ofIC of

IC Z59, checkICZ59 by sent at pin14of IC Z59, check Mux (Multiplexer)IC(Z43) substitution.

CPU

Clock is operating properly by checking

frequency, check 10.6445MHz Crystal

R46

and

R52

clock

is divided by six by the Divide By 61C

the 1.774MHz clock, pin 8 ofICZ56, and fed

Z56.

R67

and checkICZ42bysubstitution.

R64

and check Tri-State

logic

(Register)IC(Z11)

missing

Reg

logic

Monitor

reading at pin 2of IC

at pin 3ofIC

(Register)IC(Z10)

screen. Check the waveform at the

Output

Transistor (01). If the waveform

Z30 is Low, check IC

Flip/FlopIC(Z59).

Buffer

If pulses are

Z54bysubstitution.

substitution.

Check for a frequency

If the frequency is

reading at pin 6 is High, check

BufferIC(Z72)

emitter

check the voltages and

Z30

by substitution. If the wave-

Z30,

check the waveform at pin

and check

substitution.

10

Z59,

check

IC (Z22) and ICs Z23 and Z52

missing

from pin10of

Z59 and missing at pin

and check IC Z42

of Transistor

Z30

is High, check the

If pulses are pre-

Z42. If the

(Y1)

and

incorrect

If the

logic

Check

by substitu-

01,

Z41

by substitu-

Z41, check the

and the

Z30bysubstitu·

logic

for

pulses at

for

pulses at

IC Z25,

If pulses are

substitu-

of

("')

en

("')

en

w

3::J>

0

cO

men

r-::I:

-:J>

of

r-(')

m",

<-t

~:II

_en

-0,

of

14

by

:II

2

o

7

TROUBLESHOOTING (Continued)

VIDEO RAM

following

The

ICs (Z45 thru Z48 and

bit

each defective

puter,

changing the word PRINT in lines 130 and 150

LPRINT.

VIDEO RAM TEST PROGRAM

5 DATA

10

Y =6:X= 15360: POKE

20

IF (PEEK

30

POKE X,160

40

IF (PEEK

50

FOR X= 15360 TO 16383

60

FOR

70

READZ:POKE X,Z

80 IF (PEEK 90 POKE

100

IF (PEEK 110 NEXT Y 120 RESTORE: NEXT X 130 PRINT "MEMORY GOOD" : END 140

IF Y= 6THEN 150

PRINT

"CHECKS BAD" 160

IF Y= 6 THEN 50 ELSE 110

Basic program can be usedtocheck

Z61

thru Z63). The program checks

of RAM and displays on the

bit

found. If a Printer is connectedtothe Com-

the

bad

bit

message can be senttothe

1,2,4,8,16,32,128

(X)AN0

(X)

AND

Y=OTO6

(X)

ANDZ)= Z THEN 90 ELSE 140

X,O

(X)

AND

Y = 7

"BIT";Y;"OF

X,64

64)=64THEN30ELSE 150

64)

= 0 THEN50ELSE 150

Z)=O

THEN 110 ELSE 140

MEMORY LOCATION";

Monitor

the RAM

screen any

Printer by

to

the word

X;

KEYBOARD

not

Keyboard is tween Keyboard and bon cable checks good, check If pulses are

If a

groupofkeys are

Z1A and Z2A and Tri-State Inverter ICs (Z3A and Z4A) con-

to

nected cable

for

If

a single key does withanohmmeter. If the key is erratic and operation, clean the

If a wrong character shows up on the

an alpha or numeric key is pressed, check the video RAM,

to

refer guide IC

CASSETIE

Computer On the cassette motor. Type and run the program. The program will produce the waveform shown in

Figure 1 at pin 2 Off (K1) on the Expansion Interface Board.

the

and check Flip/Flop IC

(Z29)bysubstitution.

Motor

functioning.

CPU

missing,

the keys

open

"Video

will

Control Relay (K1) on the

check IC Z36 by

not

circuits.

not

contacts

RAM"

not

save programs

of

Flip/Flop IC Z59 and

Check the ribbon cable be·

Board

for

open

circuits.

for

pulses at pin11of

substitution.

functioning,

functioning.

function,

sectionofthis

(Z28)

check the pins of ICs

Also

check the key

with

a spray

Monitor

and Character Generator

onto

tape or

will

CPU

If the rib-

IC Z36.

check the ribbon

contacts

intermittent

contact

Troubleshooting

Board and Relay

screen when

will

following

toggle

cleaner.

not

turn

Basic

On and

in

The

bit

number schematic. IF the program finds a bad bit, check the schematic that RAM IC by

NOTE:NoRAM IC is used comparing

indicates

gram IC

Z30 by

Tri-State RAM IC the RAM IC checks good, check the Tri-State

with

ated VIDEO SYNC

No vertical sync. Check the waveform at pin

(Z32).

IC substitution. waveform at pin 8 of IC Z57. If the waveform is

8,

check

pin C26

and C27 and check IC Z57 by

form is present at pin

No horizontal sync. Check the waveform at pin11of Counter IC

substitution.

by form at pin 8 check the Horizontal Center Control

C21

and present at pin 8 of IC

No vertical or horizontal sync. Check the waveforms at pin

of

IC Z5. If the waveforms are missing, check ICZ5by

8 substitution.

R28

and

that each RAM IC produces is noted on the

for

the RAM IC that produces that

substitution.

for

bits

5 and 7

bit

6 is bad and

substitution.

Buffer

ICs

(Z44

outputs

and check ICZ6by

to the data lines. If a bad

the defective

If

the

waveform is missing, check IC Z32 by

If

the

Vertical Center Control

8,

(Z50).

If the waveform is

If the waveform is present, check the wave·

of

IC Z6.Ifthe waveform is

Z6,

If the waveforms are present, check Resistors

R29

and Sync Amp

bit6.Bit 6 is produced by

with

a NOR Gate IC Z30. If

bits

5 and 7 are good, check

and Z60) are usedtoconnect

bitbysubstitution.

waveform is present, check the

check IC Z5 by

substitution.

missing,

(R20),

substitution.Ifthe waveform is

check ICZ5by

Transistor

bit

Buffer

11ofCounter

(R21),

substitution.

missing

Capacitors C20

substitution.

(02).

and check

the

pro-

the

is found and

associ-

missing

Capacitors

If the wave-

check IC Z50

at pin

10

FORX=1TO100

20

OUT 255,3: OUT 255,0

30

NEXT X

40

OUT 255,4: POKE 14308,0

50

at

8,

FORX=1TO100

60

OUT 255,7: OUT 255,4

70

NEXT X

80

POKE 14308,1: GOTO

If

the

Cassette ing sound from RelayK1on the clicking, check Relay Driver IC ween Low and High. If the foralogic pin 3 of IC Z41. If the Z41, check IC correct reading at pin 1 pin 9

check RelayK1contacts

the

connections

K1isnot

(Z41).

reading that toggles between Low and High at

at pin3,check RelayK1and Diode CR3. If the

of

Flip/Flop IC

Figure 1

10

Motor

is not

switching

CPU

at pins 1 and 3ofConnector

clicking,

The

Z41bysubstitution.

ofICZ41

check the

logic

reading should be

logic

reading is incorrect at pin 3ofIC

is incorrect, check

(Z59).

If pulses are present at pin

3.5V 5ms

OV DC Reference

On, listen

Board. If the Relay is

withanohmmeter

logic

reading is correct, check

If the

foraclick·

and

toggling

reading is

for

pulses at

J3. If

bet-

reading at pin 1 of

logic

9,

8

TROUBLESHOOTING (Continued)

check IC Z59 by checkICZ25 by

If the Cassette relay

contacts

CR9 and CRW.

If the Computer will not save programs the waveform shown in Figure 1 at pin 2ofIC waveform is present, check Resistors check pin 5ofConnector J3 for good connection.ifthe waveform is missing at pin 2ofIC pin 9ofIC Z59. If pulses are missing, checkICZ25 by substitution.

IC

Z59 by

If the Computer a2Vpop, J3. Type and run the

10

X= INT(255)

20

PRINT"X= "; X

30

OUT 255,0: GOTO 10

The number X that appears on the

255

when the 1kHz signal is injected at pin 4ofConnector

J3 and

127 rect, check for pulses at pin10ofICZ4. ing, check the voltages and components associated pins 1 thru14ofICZ4.

substitution.

Motor

and check

If pulses are present at pin 9ofIC Z59, check

substitution.

will

1kHz sinewave audio signaltopin 4ofConnector

with no signal injected. If the numbersare incor-

not load a program from tape, connect

If pulses are missing at pin

runs all the time, check for

for

possible shorted Zener Diodes

onto

tape, check for

R53,

R54

and

Z59, check for pulses at

following

Basic program.

Monitor

screen should be

If pulses are miss-

sticking

Z59.Ifthe

R55

and

with

SCHEMATIC NOTES

~

Circuitry Circuitry used in some versions

8 See parts

....

Ground

Item numbers in rectangles appear in the alignment/adjust-

Supply voltage maintained as shown at input. Voltages measured Voltages and Waveforms taken

Terminal Resistors are Value in ( ) used in some versions.

not

used in some versions

list

ment instructions.

with

mode (Main noted. Waveforms taken SweeplTime set forDCcoupling on

SwitchtoAC

is measured when necessary. Each waveform is 9 cm width

withDCreference voltage given at the

of

each waveform. Time in

reading at the endofeach waveform.

title

switch

input

identification

'hWorless, 10% unless noted.

9,

If pulses are present at pin 10ofICZ4and the cassette modification check pin9,check Diodes CR200 and CR201, Resistor check ICs Z1C and Z2C by ent at pin 9 ofICZ24, check for pulses at pins 8 and13of Z24

and pins 9 and10ofICZ25. If pulses are missing from pin 9ofIC Z25, check Tri-State processor IC pulses are missing at pin10ofICZ25, and

Z54bysubstitution.

If

pulses are present at pins 9 and10of at pin13of are present at pin13ofICZ24 check IC

If pulses are present at pin 8ofIC pin 6ofIC Z25.Ifpulses are present at pin 6ofIC check Tri-State missing at pin 6ofIC Z25. If pulses are present at pin 4ofIC substitution. ICs Z22, Z23,

If RelayK1on the Expansion Interface Board is ating, refertothe

shooting

digital

meter. with

screen displayed) unless otherwise

with

in Calibrate position, scope

"0"

to view waveforms

reference voltage waveforms.

JLsec.

may

not

be found on unit.

CounterIC(Z1C)

for

pulses at pin 9 of IC Z24. If pulses are missing at

(Z40)

and ICs Z23 and

IC Z24, check IC Z25 by

Z24bysubstitution.

BufferIC(Z44)bysubstitution.

If pulses are missing at pin 4ofIC Z25, check

Z52

and Z40 by

"Cassette"

guide in the Expansion Interface Folder CSCS3-A.

computer

triggered scope and

per cm, given

in Power Up

afterDCreference

bottom

and IC Z2C has been added,

substitution.

and

Z25, check for pulses at pin 4ofIC

substitution.

input

line

with

pop

If pulses are pres-

BufferIC(Z22),

Z52bysubstitution.

check ICs Z36,

IC Z25 and missing

substitution.

missing

section

at pin 8ofIC

Z24,

check for pulses at

Z25, check IC Z25 by

R200

and

IC

Micro-

Z52

If pulses

Z24,

not

Z25,

oper-

If pulses are

of the Trouble-

If

(")

en

(")

en

(,,)

::D

~~

oS!

cO

mC/)

'-z

-~

'-0

m"

<-I

~::D

_C/)

-eo

o

NOTE: Logic probe readings taken

Up mode (Main

wise noted. Logic Probe Display L=

Low H = High P= Pulse

'"

= Open (no

light

on)

title

screen displayed) unless other-

with

computer in Power

9

::D

3:>

2

0

cO

men

....

::I:

->

....

0

m"

<~

~::D

_en

-~

o

Z56

PIIIJ

CPU BOARD A

10

1

HowardW.Sam,

'IUAiiiI.f.i3i

Photo

CPU BOARD

23

Z4

1

P 1

Z8

Zll

PI

1 P 1

PI

Z12 Z13 Z15

1

PI

1

pI

Z16

Z17

1

PI

Z2

1

PI

1

Z19

PI

Z20

1 P 1

Z38

PI

Z39

1

PI

N 1

Z22 Z23

PI

N 1

PI

N 1

255

PI

240

1

(')

CJ)

(')

CJ)

CN

CPU BOARD

22

Z42 Z43 Z25 Z44

P 1 P P 1 P

\

1

p

P

Z51

~

272

P "

Z36 Z73

PI

1

PI

1

CPU BOARD

11

1

2

3 4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

1

27

28

29

30

A

B

C

D D E

A

B

C

E

F F

G

H

G

H

::tJ

3:»

2

0

cO

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r-~

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r-C')

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<-4

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-CD

0

J

K

L

M

N

1

CPU

BOARD A Howord W.

12

2

3

4

SamslC;@.UUaWPhoto

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27 28

29

CPU BOARD

J

K

L

M

N

30

21

CPU BOARD GridTrace LOCATION GUIDE

Cl C2 C3 C4 C5 C6 C7

C8

C9

Cl0 B-19 Cl1 Cl2 C13 C14 C15 C16 C17 C18 C19 C20 C21

C22 C23 C24 C25 C26

C27

C28 C29 C30 C31 C32 C33 C34 C35 C36 C37 C38

C39

C40

C41

C42

C43

C44

C45

C46

C47 C48 C49

C'50

C51

C'52 C'53 C'54 C'55

C56

C'57

C58 C59 C60 CRI CR2 CR3

CR4

CR5 CR6

CR7 CR8 CR9 CRl0

JIA J2 J3

6-4 C-4 C-6 C-5 0-3 0-4 0-5 B-9 C-9

6-20 C-19 C-21 0-19 0-20 E-14 E-17

E-19 E-22 F-5 F-6 F-l0 F-26 F-2 G-2 L-2 M-3 G-14 G-15 G-17 G-18 F-19

G-20

G-21 H-4 H-6 H-l1 H-25

1-3 1-4 1-13 1-21

J-2

J-9 J-l0

J-18 J-26 K-2

K-15

L-6

L-l1

L-14

L-18

L-21 L-23 L-26

0-29

H-18

M-14

J-22 C-9 0-6 E-2 F-2 F-2

G-2

B-6

C-2

0-2

A-6 A-4 A-I

Kl 01 02 03

Q4

05 06

Rl R2

R3

R4

R5

R6 R7 R8 R9 RIO

Rll

R12 R13 R14 R15 R16 R17 R18 R19 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29 R30 R31 R32 R33 R34 R35

R36

R37

R38

R40

R41

R42

R43 R44 R45 R46 R47 R48 R49 R50 R51 R52 R53 R54 R55 R56 R57 R58 R59 R60 R61 R62 R63 R64 R65 R66 R67

C-2 C-3 C-4 A-12 B-16 6-20 6-22 6-12 B-12 6-12 B-12 A-19 A-19 A-19 B-19 6-19 A-20 A-20 A-20 6-20

B-20

C-20

0-22

C-24 C-5 C-l

0-1

C-3

0-3

0-3 0-4 0-4 C-4 0-4 0-6 E-2 E-2 E-2 E-2 F-2 F-2 F-4 F-12 G-3 G-3 G-4 M-2

H-2 H-2 H-22 H-25 J-ll J-25 J-26 J-2 K-2

K-2

K-19

K-22

L-4 L-17

M-18 M-19 L-20 L-22 0-29 M-21

J-3

R67A R68 R69 51

52 Yl

Zl

Z2

Z3 Z4

Z5 Z6 Z7

Z8

Z9

Z10

Z11

Z12

Z13

Z14

Z15

Z16

Z17

Z18

Z19

Z20

Z21

Z22

Z23

Z24

Z25

Z26

Z27 Z28 Z29 Z30 Z31 Z32 235 Z36 237 Z38 239 Z40 Z41 Z42 Z43 Z44 Z45 Z46 Z47 Z48 Z49 Z50 Z51 Z52 Z53 Z54 Z55 Z56 Z57 Z58 Z59 Z60 Z61 Z62

263

Z64

Z65

Z66

Z67

Z68

Z69

0-1

N-18 N-17 6-7 6-29 H-2 C-19

C-20

C-25 E-3 E-4

E-6

E-7

E-8

E-9 E-l1 E-12 E-13 E-14 E-15 E-17 E-18 E-19 E-20 E-21 E-23 E-24 E-25 E-27

G-3

G-4

G-6

G-7

G-8

G-9

G-l0

G-12

G-13

G-19

G-20

G-21

G-23

G-24

G-26

J-2 1-3

1-4

1-6

1-7

1-8

1-9

1-11

1-12

1-13

1-19

1-20

1-21

1-23

1-24 L-2 L-3 L-4 L-6 L-7 L-8 L-9 L-ll L-12 L-13 L-14 L-15 L-17 L-18

Z70 Z71 Z72 Z73 Z74 Z75

276 L-27

L-19 L-20 L-21 L-23 L-24 L-25

(")

en

(")

en

W

:II

s:~

O~

cO

mUl

'::I:

-~

'0

m"

~-I

,:II

_Ul

-00

0

13

5

OV(C)

LEVEL II ROM BOARD A

Howard

W.

Sam.

[iliiWiii;f.t3i

pl. 1

ZlA

Photo

pl',

Z4A

r

R1A

PARTIAL KEYBOARD A

14

Howord

W.

Saml

[ilii;ijiiiid3i Photo

PARTS LIST AND DESCRIPTION

When ordering parts, state Model, Part Number, and

Description

SEMICONDUCTORS (Select replacement transistor for best results)

VI

ITEM

No.

CRI CR2

CR3

thru

CR7 CR8 CR9,10

CR200,201 Ql

Q2 Q3

Q4

Q5

Q6

ZI ZlA

ZIB ZlC Z2

Z2A Z2B

Z2C Z3A Z3B Z4

Z4A Z5 Z6

Z7

TYPE

No.

1N4735

.5M5.

1ZS3

lN5231

lN4148

MOA202 3N255(1)

1N982A lN982

lN4148

MPS3904

2N3904

MPS3906 MJE29

T1P29

TIP29A

2N6594

MPS3906

MJE34 MCl723CP SN74LS05N

8044364(3) MC14040B

MCI723CP SN74LS05N 8044732

MC14001B 74LS368AN

SN74LS42N MC3401P LM3900

74LS368AN

MM74COON MM74C04N

CD4069N(

SN74LS74AN

REPLACEMENT

MFGR.

PART No.

4800021 4800022

4800002

4800023

4800026 4800002

4822001 4822003

4820004

4824003 4822003 4824002 3100001

3102009

3100001 3102009

3102025

3100002 3102025

3102026 3102027

1) 3102015

GENERAL ELECTRIC NTE

PART

No.

GEZD-6.2

GEZD-5.1

GE-514

GE-167 GE-167 GEZD-75

GEZD-75

GE-514

GE-123AP

GE-82 GE-241 NTE196 GE-302 GE-302

GE-74 GE-82 GE-69A GE

IC-260

74LS05

GE-4040 GE

IC-260

74LS05

GE-4001

74LS368A 74LS42

74LS368

74LS74A

NEW·TONE

PART No.

NTE137A NTE5010A NTE5010A NTE519

NTE167 NTE167 NTE5046A NTE5046A NTE519

NTE123AP NTE123AP NTE

159

NTE291 NTE291

NTE219 NTE159 NTE153 NTE9230 NTE74LS05

NTE4040B NTE923D NTE74LS05

NTE4001B NTE74LS368 NTE74LS42

NTE992 NTE992

NTE74LS368 NTE74COO NTE74C04 NTE4069 NTE74LS74A

II 13J\31 I 13COW

09'S~:U

)t~VHS

OICVij

PHILIPS

ECG

PART No.

ECG137A ECG5010A ECG5010A ECG519

ECG167 ECG167 ECG5046A ECG5046A

ECG519 ECG123AP

ECG123AP ECG159 ECG196 ECG291 ECG291

ECG219 ECG159

ECG153 ECG923D ECG74LS05

ECG4040B ECG923D ECG74LS05

ECG4001B ECG74

LS368 ECG74LS42 ECG992 ECG992

ECG74

LS368 ECG74COO ECG74C04 ECG4069 ECG74LS74A

ESOSO

SK6V2/137A

SK5Al/5010A SK5A1/5010A SK3100/519

SK364 SK36471167 SK75A/5046A SK75A/5046A SK3100/519

SK3854/123AP SK3854/123AP SK3466/159

SK3440!291 SK3440/291

DATA

RCA

PART

No.

7/16

7

SK3054/196

SK3173!219 SK3466/159 SK3274/153 SK3165/923O

SK74LS05

SK4040B SK3165/923D SK74LS05

SK4001B SK74LS42

SK3688/992

SK4069UB

SK74LS74A

WORKMAN

PART

No.

WEPI

154/1

WEP1411/5010 WEP1411/5010 WEP925/519

WEP1052/167 WEP1052/167 WEP1452/5046 WEP1452/5046 WEP925/519

WEP736/123A WEP736/123A WEP62/159 WEP756/196 WEP780!291 WEP780/291

WEP760!219

WEP62/159 WEP746/153 WEP2331

WEP2331

WEP2

WEP4069/4069

37

1 9230

19230

272/4001

ZENITH

PART

103-Z9008 103-279-10 103-279-10 103-131

212-Z9001 212-Z9001

103-131

121-Z9000A

121-Z9003

121-987~3

121-Z9047

121-Z9058

121-Z9003

121-988~3

121-Z9020 HE-443-818

HE-443-760 221-Z9020 HE-443-818

905-125

B

HE-443-807 HE-442-71 HE-442-71

905-233 905-260

HE-443-730

No.

0:

PARTS LIST AND DESCRIPTION (Continued)

When ordering parts, state Model, Part Number, and Description

SEM.ICONDUCTORS (Select replacement transistor for best results)

ITEM TYPE

No. No.

Z8

Z9 Z10,11 Z12 SN74LS93N

Z13

thru Z20 Z21 Z22

Z23

Z24

Z25 Z26 Z27 Z28

Z29 Z30 SN74LS02N

Z31 Z32 SN74LS93N

Z35 SN74LS157N Z36 SN74LS32N Z37

Z38,39 Z40

Z41

Z42 Z43 Z44 Z45

thru

Z48

SN74LS153N SN74LS04N

SN74LS 166N

M::I8116E

SN74LS156N SN74LS36 SN74LS32N

SN74LS132N SN74LS32N SN74LS20N SN74LS175N SN74LS 174N

8046670

MCM6670P

SN74LS157N

SN74LS02N SN74LS367AN

D780C-l

Z80 3110001

MC75452P

75452

SN74LS04N SN74LS 157N SN74LS367,4.N 21L02B 2102AN-4L

7,4.N

PART

3102019 3102008 3102021 3102017

3108009

3108003(2)

3102028 3102024 3102014

3102018 3102014 3102011 3102023 3102022

3108001 3102007 3102020 3102017

3102020 3102014 3102007

3102024

3106002

3102008 3102020 3102024

3108002

MFGR.

No.

GENERAL ELECTRIC

PART No.

74LS153 74LS04 74LS

166

74LS93

74LS367A 74LS32 NTE74LS32

74LS132 74LS32 74LS20 74LS175 74LS 174

74LS02 74LS 157

74LS93

74LS 157

74LS32

74LS02 74LS367A

74LS04 74LS157 74LS367A

NEW·TONE

NTE

PART No. PART No.

NTE74LS153 NTE74LS04

NTE74LS93 NTE2117 ECG2117

NTE74LS367

NTE74LS132 NTE74LS32 NTE74LS20 NTE74LS175 NTE74LS 174

NTE74LS02

NTE74LS 157

NTE74LS93

NTE74LS 157 NTE74LS32 NTE74LS02

NTE74LS367

NTE75452B NTE75452B ECG75452B

NTE74LS04 ECG74LS04 NTE74LS157 ECG74LS157 NTE74LS367 NTE2102

NTE21

02

REPLACEMENT

PHILIPS

ECG

ECG74LS 153 ECG74

LS04 ECG74LS ECG74LS93

ECG74LS ECG74LS367 ECG74LS32

ECG74LS132 ECG74LS32 ECG74 ECG74LS175 ECG74LS 174

ECG74LS02 ECG74LS 157 SK74LS 157 ECG74LS93

ECG74LS 157 ECG74LS32

ECG74LS02

ECG74LS367

ECG3880 ECG3880 ECG75452B

ECG74LS367 ECG2102 ECG2102

166

156

LS20

DATA

RCA

PART No.

SK74LS 153

SK74LS04 SK74LS93

SK74LS156

SK74LS367

SK74LS32

SK74LS20

SK74LS175

SK74LS174

SK74LS02 SK74LS93

SK74LS 157

SK74LS32

SK74LS02

SK74LS367 SK2880!3880 SK2880!3880

SK74LS04 SK74LS157 SK74LS367

WORKMAN

No.

PART

ZENITH

PART

No.

HE-443-755 HE-443-892

HE-443-904

HE

-443-85

HE-443-875 HE-443-879

HE-443-875 HE-443-798 HE-443-752 HE-443-879

HE-443-779 HE-443-799

HE-443-799 HE-443-875 HE-443-779

HE-443-857 HE-443-881

HE-443-881

HE-443-74

HE-443-755

HE-443-799

HE-443-857

7

PARTS LIST AND DESCRIPTION (Continued)

When ordering parts, state Model, Part Number, and Description

SEMICONDUCTORS (Select replacement

ITEM TYPE MFGR.

No.

Z49 Z50 Z51 Z52 Z53

Z54 Z55 Z56 Z57

Z58 SN74LS92N Z59 Z60 Z61

thru

Z63 Z64 SN74LS 157N

Z65 SN74LS93N Z66 Z67,68 Z69,70

Z72

Z73

Z74

Z75,76

No.

SN74LS157N SN74LS93N SN74LS 157N SN74LS04N SN74LS 132N

SN74LS30N SN74LS367AN SN74LS92N M'174C04N

CD4069CN( 1)

SN74LS 175N SN74LS36 21L02B 2102AN-4L

SN74LSllN SN74LS36 SN74LS74AN

SN74LS36 SN74LS32N SN74LSOON SN74LS367AN

7AN

3102020 3102017 3102020 3102008

3102018

3102013

3102024

3102016

3102027

3102016

3102023

3102024 3108002

3102020

3102017 3102010 3102024 3102015

3102024 3102014 3102006 3102024

PART No.

transistor

GENERAL ELECTRIC

PART No.

74LS157 74LS93

74LS157 74LS04 74LS

132

74LS30 74LS367A

74LS 175 74LS367A

74l..S

157

74LS93 74LSll

74LS367A NTE74LS367 74LS74A

74LS367A NTE74LS367 74LS32 74LSOO 74LS367A

for

best results)

NEW·TONE

NTE ECG

PART No.

NTE74LS

NTE74LS93

NTE74LS157

NTE74LS04

NTE74LS132

NTE74l..S30 NTE74LS367

NTE74C04 NTE4069 ECG4069

NTE74l..S 175

NTE74LS367 NTE2102 NTE2102

NTE74LS 157 NTE74LS93

NTE74l..S11 NTE74LS74A

NTE74LS32 NTE74LSOO

NTE74LS367

REPLACEMENT DATA

PHILIPS

PART No.

ECG74LS

157

ECG74LS93 ECG74LS 157

ECG74LS04 ECG74LS132

ECG74LS30 ECG74LS367 ECG74LS92 ECG74C04

ECG74LS92 ECG74LS 175 ECG74LS367 ECG2102 ECG2102

ECG74LS 157 SK74l..S157 ECG74LS93 SK74LS93 ECG74l..S11 ECG74LS367 ECG74

ECG74LS367 ECG74LS32 ECG74LSOO ECG74

157

LS74A

LS367

RCA WORKMAN

PART No.

SK74LS 157 SK74LS93

SK74LS157 SK74LS04

SK74LS30 SK74LS367

SK4069UB

SK74LS 175 SK74LS367

SK74l..S11

SK74LS367

SK74LS74A

SK74LS367

SK74LS32

SK74LSOO

SK74LS367

PART No. PART No.

HE-443-799 HE-443-799

HE-443-755

HE-443-879

HE-443-732

HE-443-857 905-233

WEP4069/4069

905-260

HE-443-752

HE-443-857

HE-443-799 HE-443-864

HE-443-857 HE-443-730

HE-443-857 HE-443-875

HE-443-728

HE-443-857

ZENITH

.....

(1)

NumberonunIt.

(2)

Used

(3)

2e~.

In

4K

8044732

versIons.

used

In

pJ~ce

of

8044364

In

e~rly

versIon

II 131\31 I

OS-SI:t.l

of

LevelII.

>lO"HS

1300W

OIO"1:t

PARTS LIST AND DESCRIPTION (Continued)

When ordering parts, state Model, Part Number, and

Items

not

CAPACITORS

listed

Description

~re

norm~1Iy~v~ll~ble~t10c~1

distributors.

ITEM

No.

C20 C24

RATING

330 N470 50V 330

50V 50V

10%

50V

10%

220 N220

220

5% 5%

CONTROLS (All wattages

ITEM

NO.

R5 Rl0

R20

R21

5V 10V

Horiz

Vert

FUNCTION

Adj

ust

Adj

ust

Center

MFGR.

PART

1500062 1500061

Y2

watt,

RESISTANCE

1000 1000 4750019 lOa< 4750018

lOa<

RESISTORS (Power and Special)

R1A R18

ITEM

No.

Res I

5.6

stor 5%3WWW

Network

RATING

(ll

No.

ITEM

No.

C25

or

less, unless listed)

MFGR.

PART NO.

4750019

4750018

MFGR.

PART No.

4717003

RATING

220 N220

220 50V

REPLACEMENT DATA

50V

5%

10%

NOTES

NEW·TONE

PART No.

MFGR.

PART

1500061

WORKMAN

PART No.

No.

(1)

Contains

nine

4700

10%.

MISCELLANEOUS

ITEM

No.

CR1A Kl PTl Sl S2 SW47 thru SW99 Yl Zl

Z71

PART

LED

ay

Rei Power SuppI y Switch Swl

tch

Switch

Crystal Shunt Shunt Keyboard P.C.

Board

P.C.

Board

NAME

MFGR.

PART

No.

2400025

4500001

4000004

5102008 Power 5102009

2300004

2100041

2100041 5100013 1700069 1700070

Power,

Motor

Reset Key

10.6445MHz

CPU

Keyboard

CABINET & CABINET PARTS (When ordering

WIRING DATA

Use Use

BELDEN BELDE

Shielded

General-use

Hook-up

Unshielded

Wire

Hook-up

Wire

••••••

Red(1.6V 118mA)

Control

specify

No.

8401 8208

o.

8529 8522

model, chassis & color)

or

8421

(Two-Conductor) (Sol (Stranded)

NOTES

(Single-Conductor)

id)

Avai

lable

Avai

in13Colors

lable

in13Colors

18

1.

Use an

isolation

2.

Maintain AC line voltage at rated input.

3.

Remove AC power from the

of

typicalESdevices are integrated

4.

Use extreme static

electricity.

ly available

5.

Use a grounded-tip, low voltage soldering iron.

6.

Use an

isolation

7.

Do

not

removeorinstall

8.

Do

not

use freon·propelled sprays. These can generate

transformer

caution

discharging

when handling the printed

Drain

(times

for

servicing.

computer

off

any

electrostatic

wrist

strap device. This should be removed

10)

probe on scope.

boards, floppy

SAFETY PRECAUTIONS

system before servicingorinstalling

circuits

and

semiconductor

circuit

boards. Some

charge on

disk

drives, printers,orother

your

electrical

body by

"chip"

touching

charges

electrostatically

components.

semiconductor

a known earth ground. Wear a commercial-

priortoapplying powertothe

peripherals

with

sufficienttodamage

sensitive devices. Examples

devices can be damaged easily by

unit

computer

systemACpower On.

semiconductor

under test.

devices.

9. Periodically examine the AC power cord

10.

The

computer

vents.

11.

Instructions cabinet. This could cause

12.

Never expose the

possible

near

13.

Never leave the from AC

14.

Do

not

15.

Unplug AC power cord from

16.

Never use cabinet. Make sure the

system

should be given, especiallytochildren, that

water sources.

outlet

allow anythingtorest on AC power cord.

liquidsoraerosols

cabinet is equipped

computer

during

lightning

computer

shock

systemtowater. If exposedtowater

system unattended or plugged

storms. g0

outlet

directly

for

damagedorcracked insulation.

with

ventstoprevent heat build-up. Never block, cover,orobstruct

or equipment damage.

before cleaning

on the

computer

system is

disconnected

LINE DEFINITIONS

AO

Thru A

15

BIT

0 Thru BIT 7

CAS Column Address Strobe CHAIN CLOCK CTR DO

Thru 07 Data Lines ENABLE Enable HALT Halt HORV Horizontal Drive HI High IN INT Interrupt INTAK Interrupt Acknowledge

IORC KRO

Thru KR7 Keyboard Row Lines

KYBO Keyboard

L2,

L4,

L1, LATCH Latch

LBO MOO MI

MOOSEL . . . . . . . . . .

La

Thru LB5

Thru

M07

..

. Mode Select

Any Bar above any alphabetical

Address Lines

Clock

Counter

Input

1npuUOutput Request

Memory Data Lines

or

numerical

objects

into

the AC

computer

system.

system. Spray on

from

MREC Memory Request MUX OUT

RAM Random Access Memory RAS Row Address Strobe RD ROM

ROM B Read Only Memory B SHIFT SyNC SYSRES System Reset TEST Test VCLR Vertical Clear VORV Vertical Drive

VIO

WAIT Wait

WR ZOO

ZIORC

ZMREC

ZRO

ZWR

combination

these

should

not

turn the

outlet

be dropped or pushed

unit

Off. Do not place the

for

long periods of time. Remove AC plug

into

the ventsofthe

computer

system

3:

men

'::x:

-:J>

'0

m"

cloth

and then applytothe

the AC power line. =

•.............................

Thru

Z07

indicates line active in a low

(0)

Read

state.

computer

Only

system,

Multiplex

Memory

~-1

Output

Read

Shift

Sync

Video

Write

::D

:J>

C

::D

~

o

19

MISCELLANEOUS ADJUSTMENTS

12V

AND5VADJUSTMENT

NOTE: Perform

Connect the inputofaDCvoltmetertopin 3ofRegulator IC (Z2).

Adjust

Connect the (21).

Adjust

HORIZONTAL AND VERTICAL CENTERING

12V

adjustment before5Vadjustment.

the 12.0V

inputofaDCvoltmetertopin 3ofRegulator IC the5VAdjust

Adjust

Control (Rl0) for 11.9V.

Control

(R5)

for 5.0V.

Z3 PINS

1·16 2-15 3-14 4·13 5-12 6·11 7-10 8-9

LEVEL I BASIC

Open Shunted Shunted Open Shunted Open Shunted Shunted Shunted Shunted Open Shunted

LEVEL BASIC

Shunted

Shunted Shunted

Shunted

II

Type and run the following Basic program to produce a rec· tangle on the

10

CLS: FOR X =0 TO

20

IF X>47 THEN

30

SET

40

SET

50

NEXT X

60

GOTO

Adjust Center Control screen.

ROM

SELECT SHUNT (23)

Rom Select Shunt Level IorLevelIIBasic ROMs are installed. Use the follow· ing chart to determine which pins are shunted.

Monitor

(O,X):

SET (127,X)

(X,O):

SET (X.47)

60

the Horizontal Center Control

screen:

127

40

(R21)

to center the rectangle on the

(Z3)

is set up in accordance to whether

(R20)

and Vertical

Monitor

RAM SELECT SHUNT (271)

RAM Select Shunt amountofRAM memory Use the following chart to determine which pins are shunted.

Z71 PINS

1-16 2-15 3-14 4-13 5-12 6-11

7-10 8-9

(Z71)

Is set up in accordancetothe

(4K

or 16K) installed on

4K RAM

Open Shunted Open Open Shunted Shunted Open Open Shunted Shunted Open Open Open

16K RAM

Shunted

Open Open

CPU

Board.

CASSETTE MODIFICATION COUNTER BOARD

20

A

Howard

5.0V(A)

W.

Sam.

Z2C

lilii·AIIii-d31

1

Photo

1

2

3 4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

1

27

28

29

30

A

B

C

D D E

A

B

C

E

F F

G

H

G

H

::tJ

3:»

2

0

cO

mC/)

r-~

-»

r-C')

m",

<-4

~::tJ

_C/)

-CD

0

J

K

L

M

N

1

CPU

BOARD A Howord W.

12

2

3

4

SamslC;@.UUaWPhoto

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27 28

29

CPU BOARD

J

K

L

M

N

30

21

Z4

1

P 1

Z8

Zll

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Instructions

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SAFETY PRECAUTIONS

NOTE: Before servicing

precautions

Before checkofthe The service device become

ing.

1.

Comply locatedonor monitor

2.

WARNING: video

Any

jacks, etc ment the user. Any the

3. display supply.

with ween the very cant

4.

5.

and the

returning

built

into

defective

display

design

limited

switches,

may

and

manufacturer's manufacturerofresponsibility property

HOT CHASSIS WARNING: The

monitors

is

solidly may be serviced if

the

power

nected

to the

an AC

low

reading is obtained, reverse the

recheck

chassis

Some tiontothe groundisNON-ISOLATED line. The sulating altered in any way. potential the

polarityofthe chassis transformer receiver and the AC sonnel and test equipment.

Observe the original tion

should following area, (c) that

wiresorcomponentsdonot

parts.

Inspect

wiring

in all areas.

Components

should

be replaced.

"Product

any entire technician

with

chassisorpicture

to,

alter

damage resulting therefrom.

"Hot"

for

should

high

instrumenttothe

Video Display

the

instrument

or inadvertently defeated

all

caution

inside

Alterations

monitor

alterationsoradditions

circuit

grounding,

the safety

potentially

design

are

chassis

connectedtoone sideofthe AC line cord

without

plug is

grounded

voltmeter

chassis

AC reading

material

from

and a

a zeroorlow

have a secondary

main

two

ground

chassistoearth ground, regardless

AC supply. Service on

only

inserted in the

be takentoassure proper lead

areas:

(a)

voltage area,

for pinched, out·of-place,ordamaged

that

this

chassis, read and

Safety

Notice".

Monitor

must

be sure that no

by the

and safety related

the receiver cabinet and on the

tube.

of the

designorcircuitryofthis

should

not

be made.

modifications,

activeorpassive

characteristicsofthis

create a hazardous

alterationsoradditions

warranty and

connectedtoone sideofthe AC

equipmentinwhich

usinganisolation

insertedsothat

sideofthe AC supply. Check

to see of a

known

should

chassis

systems

which

Other

be performed

supply

correct

near sharp edges,

indicate

will

for

chassisofsome

earth ground. A zero

be obtained.Ifa

meter

reading.

ground

ground. The secondary

in respecttothe

are separated by in-

must

not

chassis

power

for

protectionofboth

lead dress. Extra precau·

(d)

video

evidence of overheating

follow

customer

should

manufacturer

such

auxiliary

further

personal

the

potential

be defeated

have an 85V RMS

withanisolation line between the

input

touch

Copyright

a safety

be made.

protective

during

servic·

as,

but

speaker

circuitry,

situation

will

relieve the

injury

the

chassis

transformer

chassisiscon·

exists

signifi·

power

plug and

system

in addi·

these

types

dress

(b)

AC

wiring.

thermally

Corporation.

instru·

supply

these

has

notes

not

for

void

or

video

bet·

or

power

per-

in the

Insure

hot

Radio Shack, a DivisionofTandy

or

of of

Used

6.

WARNING: The integral the same type remove, ner so equipped are handled. Keep while deflection and is remove because servicer.

7.

Protective shields are provided on protectionofboth customer. Protective

convenience

MISSING SHIELDS MUST BE REPLACED. OPERATE THIS INSTRUMENT WITHOUT THE PRO· TECTIVE SHIELDS IN POSITION AND PROPERLY SECURED.

8.

When replacing a tain place, fish shields,

9.

VIDEO INPUT COLD CHECK

With place a strumentACswitch one leadtothe jumperedACplug and leadtoeach exposed coaxial sistance megohms. Any resistance value below dicatesanabnormality tion. Repeat the position.

10.

LEAKAGE CURRENT HOT CHECK (ON COMPLETE ASSEMBLED INSTRUMENT)

Plug the AC line cord not use an Leakage Current Tester complies (ANSI C101.1 "Leakage Current for Underwriters for AC cabinet (plugs, jacks, handle bracket, metal cabinet, screwheads, metal overlays, known ticularly the chassis. Any

0.5 test. ANY MEASUREMENTS NOT WITHIN THE LIMITS OUTLINED ABOVE ARE INDICATIVE OF A POTENTIAL SHOCK HAZARD AND CORRECTIVE ACTION MUST

BE

TO

with

permission.

implosion

installorhandle the

unless

shatterproof

should

handling. On

yoke is an integral partofthe

permanently

"permanently

of

possible

that

all the

such

as:

papers,

isolation

theACplug removed from the 120VAC source,

jumper

measured

isolation

with

current

with

switch

"off"

earth ground (waterpipe,

any exposed metal part having a return path to

milliamp.

TAKEN BEFORE RETURNING THE INSTRUMENT THE CUSTOMER.

picture

number

mustbecorrectly

non-metallic

adjustment

across the

American National Standards

Laboratories (UL) 1410, (50.7). Measure

theACswitch

Reverse plug in the AC

tube

in thiS

monitor

protection.

be kept away picture

"In·Line"

attached. Do

tube breakage and hazardtothe

the service

shields

chassis

protective

resistor

on. Using an ohmmeter,

should

test.

with

directly

transformer

from all exposed metal partsofthe

current

Replace

for

continued

picture

goggles

tube away from the body

attached"

in the cabinet, always be cer-

devices are control

and

capacitor

two

which

the AC

orametering

measured

tube

are worn. People

while

type

picture

yoke from CRT

this

technician

removed

re·installed and ANY

knobs,

compartment

networks,

plug prongs. Turn the in·

connector.

not be less than

requires

switch

into

a 120 VAC

for

this

Appliances")

"on"

and repeat

control

shafts,

conduit,

must

outlet

employs

withatube

safety. Do

in any man·

picture

tubes, the

picture

not

attempt

chassis

touch

for

and the

for

servicing

DO

put

back in

insulating

covers/~

etc.

connect

the

The

this

range in·

corrective

in the OFF

outlet

check). Use a

system

Institute

with

etc.)toa

etc); par-

not exceed

and repeat

not

tubes

tube

the

NOT

other

ac-

(do

which

and

the

of

to

re-

20

4

SAFETY PRECAUTIONS (Continued)

DEVICE

UNDER

TEST

2·WIRE CORD

PLUG AS REQUIRED) GROUND

11.

X·RADIATION

The primary

state

video picture x-radiation tection, as the original. The picture and

must

High

voltage

required

high

voltage. Where used, x-radiation

cuits

(may

(READING SHOULD

NOT BE ABOVE

a.5mA)

ALL

TEST

EXPOSED METAL

SURFACES

ALSO TEST WITH PLUG REVERSED

(USING ADAPTER EARTH

AC LEAKAGE TEST

AND

HIGH VOLTAGE LIMITS

sourceofpotential

display

monitorsisthe

tube

is

specially

emissions.

the replacement

tubes

have an x-radiation

be properly in place.

must

that

involves B +, horizontal

also

For

tube

shields

be checked each

be referredtoas horizontal

\-

x-radiation in

constructed

continued

must

and

mounting

protection

©

-\0

_.~

picture

x-radiation pro-

be the same type

time

Protection

Copyright

LEAKAGE

CURRENT

TESTER

solid

tube. The

to

prohibit

hardware

any service is deflection

Corporation.

for

function

Cir-

disable

Radio Shack, a DivisionofTandy

or

hold-down)

time fertothe Technician x-radiation

Chassis

strument chassis cuits

High voltage is maintained the use and voltage exceeds nent take necessary

12. PRODUCT SAFETY NOTICE

Many have special safety-related characteristics spection necessarily be ponents placement characteristics plements such schematics its

Supplements replacement characteristics shown plements hazards.

Used

with

permission.

must

the x-radiation

Schematic

Labels

and, where used, x-radiation

specifications.

of

close

adjustments

specified

electrical

nor

can the

rated

parts

and

Bulletins.

features are

and by # on the Parts

which

in the Parts

and

Bulletins,

be checked

Protection

in the Basic Service Data and In·

for

specific

tolerance safety related

in the

specified

on the

corrective

and mechanical

are

often

obtainedbyusing

for

higher

which

are

identifiedinthis

and

Bulletins.

does

as the recommended replacement part

for

proper

operation

Circuitisserviced.

warning

high

voltage

within

high

voltage

limits,

check

chassis

identified

Listinthis

schematic

action.

parts

characteristics.

not

evident from visual in-

protection

voltage, wattage, etc.

have these special safety

Electrical

not

may create shock, fire,orother

components

by

Listinthis The use of a have

note

limits

of each

Protection

specified

afforded by

replacement

Data and

shading on the

the

Data and

limits

components

circuit.Ifhigh

each compo-

diagram and

in television

its

having

Data and

substitute

same safety

its

each

Re-

on the

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sets

These

them

com·

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~>

0

cO

men

I:I:

->

10

m",

<

m-i

I::tI

_en

-eo

::tI

52

o

5

19.QV

16.2V

MAIN

6

BOARD

18.6V(A)

A HowardW.Saml

(li1·ii.iii".,3' Photo

MAIN

BOARD GridTrace LOCATION GUIDE

C9

Cl0 C22 C23

C24 C25 C26

C27 C28 C29 C33

B-3 0-3

K-5 L-5 K-3 F-7

1-11

6-10

D-6

F-8

H-5

1 2

C34 C35 C38

C39 C40 C41 C42 C43 C44

C45 C48

3

G-5

1-5

1-7 E-6 G-6

J-,9

H-6

G-7

B-5

F-8 B-7

4

C49 C50

C51 C56 C57 C59

C60 C61 C62 C63

C64

5

E-7

0-4

0-5 J-6

1-5 C-7 0-8 B-7 B-8 F-9 F-l0

6

7

C65 C66 C68 C69 C70

m4

CR6

m7

CR8

m9 ml0

8

9

J-l0

1-10 F-l1 E-l0

0-11

F-8 J-7

1-9 H-7 C-6 E-8

m12 m13 CR14 m17 m18 m19 m20 FBI FB4 FB5 FB6 FB7

L2

10

A

B B

C

0

E E

F

G

H

J

K

L

1 2

3

4

5

6

A

HowordW.Soms

7

@jlieJI;tJiW

8

9

10

Photo

B-7 0-6 C-5 C-8

0-9 0-9

C-l0

B-7

E-l0

F-l0

0-9

C-9

K-2

11

A

C

0

F

G

H

J

K

L

11

MAIN BOARD

L3

L4 L5 Q2 Q3

Q4

Q5

Q6

Q7 Q8

Q9

Qll

Q12 Rl R2

R9

RUB R14

R15 R16 R18

R19 R20

R23 R24

R25 R28

R29

R30

R31

R32

R34

R35

R36

R37

R38

R39

R40

R41

R42

R43

R44 R45 R46 R47 R48 R49 R50 R51 R52 R53

R54

R55

R59 R60 R61 R64 R65 R66 R67 R68 R69 R70 R71 R72 R73 R74 R75 R76

R77

R78

R79 R80 R81

J-3 K-l1 E-l0 K-3 E-5 H-6 H-6

1-8 F-7 E-8 K-9

1-10 F-l0 C-2 E-2 C-2 K-7 K-l L-4 L-4 K-4 K-2 K-3 H-l0 B-9 F-8

1-4 G-5 E-6

F-5 F-5 B-5 J-7

1-6

J-8

J-6

1-8

G-6 H-6

J-7

J-6

H-7 G-7 H-9

F-9

H-9

1-6

F-6

1-9 J-8 J-9 H-8 E-7

0-7 C-2

C-6

C-8 0-9

C-8 G-9 F-l0 H-9 H-l0 H-9 H-l0

J-ll H-l0 F-ll 0-10 C-9 C-9 C-l0 K-2

(")

en

(")

en

~

•

CD

:xJ

3:>

2

0

mC/)

'::I:

->

,n

m"

<-4

~:xJ

_C/)

-0,

0

7

00

PARTS LIST AND DESCRIPTION

When ordering parts, state Model, Part Number, and Description

SEMICONDUCTORS (Select replacement for best results)

ITEM

No.

ffi4 CR6 ffi7 CR8,9 CRIO CR12

ffi13,14

CR17

ffi18

ffi19

ffi20

ffil0l

TYPE

No.

F084 F031 F060 031 F031 A-231

F084

TI031 031

A24015

F046

RC185-6

139706

119597

119597 119597 119597

138173

139706 119597 119597 119597 139706 141489

MFGR.

PART No.

GENERAL ELECTRIC NTE ECG

PART No.

GE-300

GE

-300 GE-300 GE-300

GE-300

GE-511 GE-300

GE

-300 GE-300 GE-300 GE-300 GE-510 NTE125

NEW·TONE

PART No.

NTEl77

NTE

177

NTE177 ECGl77

NTE

177 NTEI77 NTE552

NTEI77 NTE

177 ECGI77 NTEI77

NTEI77 ECGI77 NTE177 ECG177

PHILIPS

PART No.

ECG177 ECGI77

ECGI77 ECGI77 ECG552

ECG177 ECG177

ECG125

REPLACEMENT DATA

RCA

PART No.

SKOO91/177

SK9091/177

SKOO91/177

SK9091/177

SKOO91

1177

SK3130 SKOO91/177

SK9091/177

SKOO91/177

SK9091/177

SKOO91

1177

SK5010/117A

WORKMAN

PART No.

WEP10621177 WEP1062/177

WEP10621177 WEP1062/177 WEP10621177 WEPl72/506

WEP1062/177 WEP1062/177

WEP1062/177 WEPI

062/

WEPI WEP170/125

177

06211 7 7

ZENITH

PART No.

103-131 103-131

103-131 103-287

103-131 103-131

103-131

212-Z9000

ffil06

CR107 M132

CRl08 02

03

04,5 06

07

08 09

011 012 0101

T14881 A8293O-6(1)

362-3

7362-3

306-8

7306-1 112-8 1112-8 318-2 7318-2

666-1 3666-1 349-2 7349-2 303-1 7303-1

6143H827 3614-3 306-1 7303-1 M366-1 7366-1

(3)

140972 138173 (2

)

141295

141330

132830

139268

137155 141008 137340

137875 137340 140976

GE-511 NTE558 GE-511 NTE552

GE-27 GE-27

GE-123AP NTE123AP

GE-123AP

GE-82 NTE159

GE-220

GE-82 NTE159

GE-82

GE-123AP

GE-82 NTE159 ECG159

GE-82

GE-123AP

GE-123AP NTE123AP GE-82 NTE159 GE-82 NTE159

GE-38

GE-38 NTE165

NTE171 NTE171

NTE123AP

NTE194 NTE

194

NTE

159 NTE123AP ECG123AP NTE123AP

NTE

159 NTE123AP

NTE165

ECG558 ECG552

ECG171 ECG171

ECG123AP

ECG159

ECG194

ECGI94 ECG159

ECG159 ECG123AP ECG159 ECG123AP

ECG123AP ECG159 ECG159 ECG165 ECG165

SKOO00/552

5K3130

5K3201/171 SK3201/171

5K3854/123AP

5K3466/159

5K3466/159 SK3479 5K3479

5K3466/159 SK3466/159 5K3854/123AP 5K3854/123AP

5K3466/159

SK3466/159 5K3854/123AP

SK3854/123AP

5K3466/159 5K3466/159 5K3115/165

5K3115/165

WEPI72/506 WEPI72/506

WEP702/171 WEP702/171

WEP736/1 23A WEP736/123A

WEP621159 WEP62/159 WEP64/194 WEP64/194

WEP62/159 WEP62/159 WEP736/1 23A WEP736/123A WEP621159

WEP621159 WEP736/123A

WEP

736/1 23A WEP621159 WEP62/159 WEP74OB/165 WEP740B/165

103-287 103-287

121-822

121-Z9000A

121-Z9003

121-881

121-ZOO03

121-Z9003

121-ZOO00A

121-Z9000A

121-ZOO03

121-Z9003

121-Z9000A

121-ZOO03 121-Z9003 121-1029

121-1029

PARTS LIST AND DESCRIPTION (Continued)

When

ordering parts, state

Model,

Part Number, and Description

SEMICONDUCTORS (Select replacement for best results) (cant)

CRI

01 03

Q4

05

Zl

ITEM

No.

thru

Numberonun

(1)

(2)

Part Maybepart

(3)

TYPE

No.

VIOCO

BOARD

1

N5242B

lN4742 MPS3904 2N3904 MPS3906 2N3906

MPS3904 2N3904 6N135 /-P5082-4351 5082-4350

of

It.

Horlz Output

of

Ql01

PART

4800037 4822001

4822003

4822001

3106001

Transformer

In

some

versIons.

MFGR.

No.

Tl01

Part

GENERAL

ELECTRIC

PART

GEZD-12

GE-123AP

GE-82

GE-123AP

No.

140995.

No.

NEW·TONE

NTE

PART

No.

NTE5021A NTE142A

NTE123AP NTE123AP

NTE159 NTE159

NTE123AP NTE123AP

REPLACEMENT

PHILIPS

ECG

PART

No.

ECG5021 ECG142A

ECG123AP ECG123AP

ECG159 ECG159

ECG123AP ECG123AP

A

DATA

RCA

PART

No.

SK12A15021A SK12V/142A

SK3854/123AP

SK3466/159

SK3466/159 SK3854/123AP

SK3854/123AP

WORKMAN

PART

No.

WEP1423/5021 WEP1112/142

WEP736/123A WEP736/123A

WEP621159

WEP62/159 WEP736/1

WEP736/123A

23A

ZENITH

PART

No.

103-279-21 103-Z9003 121-Z9000A

121-Z9000A

121-Z9003

121-Z9000A

WIRING DATA

High

Voltage

Shielded General-use

-0

Lead

Hook-up Wire

Unshielded Hook-up Wire

••••••••••••••••••••••••

••••••••••••••••••••

••.•••

Use'BELDEN Use

BELDEN

Use

BELDEN

No.

8869 (17

No.

8401 8208 (Two-Conductor)

No.

8529 8522

09'S~:U

KV)

or

8421

(Solid) (Stranded)

II

131\31 I

(Single-Conductor)

Available

1300W

)f~'fHS

OIO'fl:j

In13Colors

S-ESOSO

PARTS LIST AND DESCRIPTION (Continued)

When ordering parts, state Model, Part Number, and Description

ELECTROLYTIC CAPACITORS

#

ITEM

No.

C113A

Items

#

For

B

SAFETY

RATING

200

250

numbers

CAPACITORS

ITEM

No.

Cl01

#

Cl02

#

Cl03

#

.18 36 .1

use

RATING

200V N750 200V

175V 175V

not

only

10%

5%

10%

lIsted

equIvalent

PAIIT

140969

are

normally

139318 142023

242290

MFGIl.

No.

replacement

MFGR.

PART

No.

avaIlable

part.

ITEM

No.

at

local

ITEM

No.

Cl05

#

Cl08

I

ClIO

I

RATING

dIstrIbutors.

.0015 1.2KV 180

125VAC

.1

RATING

MFGIl.

PAIIT

141496 143029

133343

No.

MFGR.

PART

No.

Items

For

numbers

SAFETY

#

use

not

only

listed

equIvalent

CONTROLS (All wattages

#

# #

ITEM

NO.

Rl38 R44 Rl02 Rl03

#

For

(1)

SAFETY

Number on

FUNCTION

Vert

Hold

Vert

SIze

Contrast

BrIghtness

use

unIt.

only

equIvalent

are

normally

1/2

RESISTANCE

200< 500< 500

200<

replacement

avaIlable

part.

at

local

distrIbutors.

watt, or less, unless listed)

MFGR.

PART

NO.

141022

replacement

1473351-2(1 138145 1473359-27<1) 140980 1472242-43<1 ) 140711

part.

)

NOTES

10

PARTS LIST

When ordering parts,

AND

state

DESCRIPTION

Model, Part Number, and

(Continued)

Description

RESISTORS (Power

ITEM

No.

Rl 75

#

R2

I

R9

#

R14

R23 470

#

R24

#

R34

I

R40 R47

R49 R52 R54

#

R61

#

R77

#

R80

#

Rl08

#

Rl09

#

R112

#

Rl14

#

R118

#

R121

#

R12 200

#

For

SAFETY

(1)

Number

5%2WMetal

755%2W 10

5%

75005%3W

10K

lW

56005%2W

5%

4.7

5%

56

5%

W(

2%

12K

2% 12K5%112W 1202% 1502%

5.6

5%

3.3

5% 10

5%

4.7

5%

6800

68005%

22

5%

130

5% 2200 2000 1

1305%7W

VI~O

10%5WWW

use

only

on

unIt.

5%

and

Metal

1/2W

Metal Metal

1/2W

Metal

1/2W

Metal

1/2W

Carbon

1/4W Carbon

1/2W

Carbon Carbon

1/4W

Carbon 1/4W Carbon 1/2W

Carbon 1/2W

Carbon

1/2W

Metal

1/2W

Carbon

1/2W

Carbon

1/2W

WW

7ti

WW

lOW

WW

equIvalent

Carbon

WW

lOW

(Jti

BOARD

Special)

RATING

OxIde OxIde

OxIde

FIlm

FIlm FIlm

OxIde

FIlm

FIlm FIlm

replacement

part.

MFGR.

PART No.

832075 832075 830010

832256 830147

140986 830056

132855

143031

139324

830010

140986

993151-249

143030 94

5312-1 209895 945311-128<l 249398 945312-157<l

209895 945311-128(1

4717002

09<l

REPLACEMENT DATA

NEW·TONE

PART No.

2W075 2W075 HW010

lW310 2W256 HW147 HW4D7 HW056 QW310 HW312 HW312 QW112 QW115 HW5D6 HW3D3 HW010 HW4D7 HW268 HW268 10W022

) )

IOW222

)

WORKMAN

PART No.

22-2224 22-3120

22-4114 22-2237 22-2040 22-2066 22-2253

22-2122 22-2230 22-2231 22-2042 22-2036 22-2048 22-2040 22-2116 22-2116

24-4093

24-3070

:xJ

3:»

2

0

cO

mC/)

r-:J:

-»

r-O

m"

<

....

~:xJ

C/)

-eo

o

COILS (RF·IF)

MFGR.

PART

L2

ITEM

No.

FUNOION

RF

Choke 109946

COILS & TRANSFORMERS (Sweep

,

DYl

L4

L5

,

nOl

#

(1)Incl

For

ITEM

No.

SAFETY

udes

Yoke 90° Horlz Hor1z Hor

use CR108.

HorIz4.

Vert

Hold

DrIver

I z

Output

only

FUNOION

6Irti

51mH

equIvalent

replacement

No.

Circuits)

143045 141017 141021

(1)

140995(1)

MFGR.

PART

part.

No.

L3

ITEM

No.

FUNOION

Peak I

n9

REPLACEMENT

OTHER

IDENTIFICA

1463734-504 1463734-503

1465914-503 1465914-501

liON

DATA

MFGR.

PART

130131

THORDARSON

PART

No.

11

PARTS LIST AND DESCRIPTION (Continued)

When ordering parts, state Model, Part Number, and Description

FUSE DEVICES

ITEM

NO.

,

F10l

,

Fl02

#

For

SAFETY

DESCRIPTION

1AII250V Fast-ActIng 5AII250V Fast-ActIng Plgta

II

use

only

equIvalent

DEVICE

426973

99328

replacement

part.

MISCELLANEOUS

#

I

#

ITEM

No.

OSIOI FBI FB4

FB5 FB6 FB7 FB10l L10l

P10l SIOI

VIOl

PART

Neon

Lamp FerrIte FerrIte FerrIte FerrIte FerrIte FerrIte F

errIte

Power Cord

SwItch CRT CRT Bracket CushIon

P.C.

Board

P.C.

Board

Socket

NAME

Bead Bead Bead

Bead

MFGR.

PART

No.

122608 NE-2H 119971

128456

138013

143038

142453

142639

12VBYP4

12VBNP4

141006

132272 143035 1700065 143036

Main

MFGR.

PART NO.

AC,PoJarI zed Power

AC

Power

CRT VIdeo

CRT

Cord

MountIng

NOTES

HOLDER

NOTES

#

For

SAFETY

use

only

equIvalent

replacement

part.

CABINET & CABINET PARTS (When ordering specify model, chassis & color)

PART

CabI

net CabInet Button-Power

#

For

SAFETY

12

ITEM

Back 141856 Front

Mask 142312

use

only

equIvalent

140783

replacement

No.

part.

I

Knob-BrIghtness,

#

Knob-Hor1z

ITEM

Hold

Contrast

PART

136347 124313

No.

A HowordW.Sama

[iji.ijMihD

Photo

VIDEO BOARD

13

- <

~

-

c

m

0

OJ

0

»

::J:J

C

}-

I

0

~

a.

:E

0

'"

3

'"

. 1 ..

A

'ElJJl!JUULJ;

B

l--:J

C .

[

~

••

]~~~61"~~·[j]IIII[lI!E!j~

3

--~J

5 6 7 8 9

Ifiiiii]Onn

..

; .

(~.J.;~?",.~

."

~,4

,,~~_,~,

-.

~~.

••

'f'

.r.-:

I

_10

lliJnn~1

-

•...

,.

..

j~

:

....

bJ~L'

. . C

' " .

12

13

A

B

DD~lIl1li1lilllllililllt:JDD

1~111J1I~~II~.flj-[]~

,

0

[E]1I1I1I[jDIIEJ[]~~_IJ~

G

r41r-1

H ]tt:lLJ1

••

______

rIi1nll~fjr-;ltn~rr-]

Ii8II;

__

l

.j~~'<'1

G

H

VIDEO BOARD GrldTrace LOCATION GUIDE

B-3

B-9

E-3

0-5 E-8 E-l1

1-8 C-ll E-9

F-2 F-40 H-7 H-l1 C-5 C-9 C-9 B-5 0-9 E-2

E-2

E-4

E-5

F-l0

1-3

H-8

G-8

G-9

H-l0

H-12

F-ll

E-7

I

Cl C2 C3 C4

C5

C6

C7

CRI

Ql

Q2

Q3

Q4

Q5 Rl R2 R4 R5 R6

R7

;\8

R9 RIO

Rl1

R12 R13 R14 R15 R16

R17

R18 ZI

J

1I 2

J

43

5

6

7

8

9

10

I

11I12r13

::D

~>

2

0

0°

mC/)

r-:I:

->

r-o

m",

<-4

~::D

_C/)

o

-=

A Howard W.

Sam.

[tIl

A""''''3i

i

Photo

MAIN BOARD

15

TROUBLESHOOTING AID

Note: Waveforms taken

Controls

PICTURE

NO PIC, NO RASTER: Check for AC power supply and sources generated from Horizontal

"Troubleshooting"

NO PIC, HAS RASTER: Referto"Troubleshooting"

LOWOREXCESSIVE BRIGHTNESS: Check Video and Luminance

SWEEP

NO RASTER: Check HV rectifier, Part

NO VERT DEFLECTION: Referto"Troubleshooting"

POOR

VERT LINORFOLDOVER: Referto"Troubleshooting"

POOR

HORIZ LINORFOLDOVER: Referto"Troubleshooting"

NARROW PICTURE: Referto"Troubleshooting"

VERT OFF FREOUENCY: Referto"Troubleshooting"

HORIZ OFF FREOUENCY: Referto"Troubleshooting"

SYNC

adjusted for normal operation.

with

trigged scope, Bar-Sweep generator. Schematic voltages measured

Power Supply and Horizontal

of

Horizontal

circuits.

Video

Output

Vertical

Horizontal

Vertical

Horizontal

circuit.

circuits.

Trnasformer(T101). Referto"Troubleshooting"

circuit.

Vertical

Horizontal

circuit.

Referto"Troubleshooting"

circuit.

Output

with

digital

Transformer

Video

Horizontal

meter,nosignal.

(T101).

Refer

circuit.

to

NO VERT/HORIZ SYNC: Refer

Note: Make sure

lose raster,orsync, or both, accordingtowhichever signal is

that

the problem is in the

"Troubleshooting"

Monitor

and

TROUBLESHOOTING

POWER SUPPLY

Check AC Fuses CR101, and Capacitor C110.

good, check for 133V at cathode of Diode CR101. missing,

for

Check

if

(T101),

the voltages developed

19.0V at of ResistorsR9and any sociated

HORIZONTAL

Check the Horizontal check the waveform at base

sistor

forms and Check waveform at base of Transistor 0101 and check the voltages, waveforms and

with

sistor

junctionofResistorsR9and

Capacitor

of

the voltages are incorrect, check

(011). If waveform is missing, check voltages, wave-

Horizontal Driver

012

(F101

and F102) andifopen, check Diode

If

Fuses

F101

and F102 are

If

133V is

check Resistor R112 and Power

88.3V at pin 2ofHorizontal

missing,

with

check Resistors

from

C44

and

Electrolytic

R32,

11.7V at pin 5ofTransformer

that

voltage.

Output

components

are good, check Diodes CR106 and CR108 and

associated

Transistor

R121

Transformer T101. Check

C39, 18.6V at

Transistor

of

Horizontal

components

(012). If readings at Tran-

Switch

Output

Transformer

and

R114.

R61,

16.2V at

components

(0101). If good,

Oscillator

with

Transistor

(S101).

Check

junction

n01.

if

missing,

associated

Sync

notinthe

for

of

If

as-

Tran-

011.

circuit.

Computer. If the

missing

Horizontal developed by Transformer down

the horizontal circuit.

For horizontal linearity or foldover problems, check Capacitors C108, C105, C101, C102 and C103 and Deflection

VERTICAL

Inject a vertical signal at base

sistor

(04) and check no vertical the baseofVertical Driver Transistor (06). If vertical deflection

returns, check voltages and

with

Transistor04and Preamp deflection Blanker

09),

For Diodes CR6 thru Capacitors ments and bias

Transistor

Deflection

poor

Chart"

Monochrome

from the

Output

Yoke (DY1).

deflection

does

vertical linearity or foldover problems, check

C41

circuitry

Computer

Transformer (T101). Check the voltages

for

not

(07), Vertical

Yoke (DY1) and associated components.

CR1O,

and C45. Refertothe"

and check

resistances.

Adapter fails,

to Monitor.

n01,

which

may be loading

of

vertical

is noted,

return, check

Electrolytics

for

Vertical

deflection

inject

the

vertical signal

components

Transistor

Output

Transistors

C39,

C40

Resistance Measure-

possible changes in feedback

the

Oscillator

Monitor

on the CRT. If

05.Ifvertical

and C42 and

will

the

Tran-

associated

06,

Kine

(08

and

to

16

TROUBLESHOOTING (Continued)

VIDEO

Inject

a video signaltobaseofVideo Amp on the Video Board. Check waveform at base put

Transistor

ing,

check

with

ated 8 of

IsolationIC(Z1) present at base sistor

02,

cathodeofthe CRT.

No

video Check the

Computer Video Board by sistor

(02), Video Preamp

associated

(02) on the Main Board. If waveformismiss-

voltages, waveforms and

Video

Amp

Transistors

on the Video Board.Ifthe waveform is

of

Transistor02on Main Board,

the CRT and

with

for

Computer

5.0V at pin 2 of IC Z1. andifmissing,

substitutionorcheck

components

on the Video Board.

connectedtoConnector

check

Transistor

components

(01 and04and

associated

This

voltage is

Computer. Check the

Noise

(03) and ICZ1and

Transistor

of

Video Out-

associ-

pins

check

with

supplied

Filter

(04)

5 thru

Tran-

the

P2.

by

Tran-

SYNC

No

verticalorhorizontal sync. Check voltages and wave-

forms

at base and

(03).

No

vertical sync. Oscillator associated

No CR18. circuitry.

(04).

components.

horizontal sync. Check waveformsatDiodes CR17 and

Check

collector

Check

the Horizontal Hold Coil (L4) and

of Sync Separator

waveformatbaseofVertical

Vertical Hold

Control

(R13B) and

associated

Transistor

::0

3:>

O~

cO

mCJ)

r~

->

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m",

<0004

pJ::o

_CJ)

-!Xl

o

17

....

Q)

ITEM

VIOl VIDEOBeARD

INF

RESISTANCE MEASUREMENTS

MEASUREMENTS TAKEN WITH LOW POWER OHMS METER

5

INF

6

7

8

0

1

2

3

4

730K

FIL

INF

9

10

11

12

13

14

Zl

ITEM

Q2 Q3 Q4 Q5 Q6 Q7

(1)

Reading

INF INF

E B

200

0

6000 55()(

8285 8285

may

516

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1M 114K

0

vary according to the condition of the

500K

C

1.

5M 3959 1M 1141< 355K

INF

0

ITEM

Q8 Q9 Qll

Q12

Q101

electrolytic

47K

E

1.6M

1.6M 57

INF

0 6

in the

12K

B C

325K 316K

INF

3021

circuit.

630

INF

5 5501< 7

INF

(1)

ITEM

VIDEO

BC

Q1 Q2

Q3 Q4 Q5

E B C

II,RD

182

INF

800K(1) 1327 469

47K

INF

6170 1326

2109

INF

580K 0 2290

SCHEMATIC NOTES

#

For

SAFETY

parts list.

Circuitry Circuitry

9

See parts

? Ground

Chassis Waveforms and voltages are taken from ground, unless

noted otherwise.

Item numbers in rectangles appear in the alignment/ad·

justment Supply voltages maintained as shown at input. Voltages measured Controls Terminal Capacitors are Electrolytic

noted. Resistors are Value in ( ) used in some versions.

Measurements

use

only equivalent replacement part, see

not used in some versions used in some versions

list

instructions.

with

digital

meter, no signal. adjusted for normal operation. identification

50

capacitors are50volts or less, 20% unless

V2W

may

notbefound on unit.

voltsorless,5%unless noted.

or less, 5% unless noted.

with

switching

as shown, unless noted.

19

CH1Ul

Hlll

Hl14

H1HS

_----Cl05

Cl01

R121

Cl12

Cl07

CR107

Cl06

T101

FB101

l101

o

~

l>

C/) C/)

C/)

~

o

."

<

m

:E

l',)

o

II

131\31

09·S~U

Fl02

I 13QOW

:>40VHS

OIQV~

Fl01

Cll0

ClOg

0101

C113

CR106

C10B

DS101

R123

CABINET·REAR VIEW

DISASSEMBLY INSTRUCTIONS

CHASSIS REMOVAL

screws

Remove five Disconnect Loosen and remove CRT neck chassis

Remove

and remove bracket.

from cabinet. Remove two

holding

CRT socket, HV anode and

screws

holding

cabinet back and remove back.

assembly

knobs

control

brackettocabinet

ground

and remove main

from

cabinet

SERVICING IN THE FIELD

CRT IMPLOSION PROTECTION AND CLEANING

Implosion cleaning

FUSE DEVICES

A 5-amp and 1-amp fuse are used for (See Placement Chart.)

21

protection

accomplished

is an integral partofthe

without

CRT removal.

AC

picture

line

wires.

front.

front

tube,

protection.

CRT REMOVAL

Follow

"Chassis

soft

on a CRT to cabinet CRT by the neck.

HORIZONTAL OSCILLATOR

Adjustmentofthe proper Cabinet·Rear View.)

CENTERING

Centeringisaccomplished magnetic

setting

Removal" procedure and lay set facedown

protective

rings

surface. Remove four

front

and

lift

horizontal

of the horizontal hold coil. (See photo,

located on the yoke rear cover.

CRT

outofcabinet. Do

holdisaccomplished

by proper

screws

adjustmentoftwo

holding

not

lift

by the

~

~.

o

~

cn-

a::..J

~w

~>

O~

<-

J:..J

cnw

0

-0

o~

<

a::

<

C")

en

(J

en

(J

....

•

~

COMPUTCRCACTsn.

'_

IL_ln_/""\__,_

'

KEYBOARD, CPU BOARD

See Folder CSCS3

RADIO SHACK TRS·80

Miii,,;,0~D_E

..L..1.,LE..V.E;,;L;,.;I..I _

EXPANSION INTERFACE

(")

en

(")

en

w

•

»

PRELIMINARY SERVICE CHECKS

ENCLOSED

INDEX

Page Disassembly GridTrace Location Guide

Expansion Interface Board 8,13 IC Pinouts & Terminal Guides 5,16 Line

Definitions Logic Chart Miscellaneous Parts

Instructions

Adjustments

List

I

~

Howard

....

1.

Th.

listing of any

constitut.inony Howord W. Soms & Co. Inc..as'a replacement

Inlormotion

Irom manufacture..01

case0(-.commendation,

port.

4300 West 62nd Street, P.O. Box 7092,

available

The

numbers furnished'aHoword W. Soms & Co.. Inc ..bythe the

ponlcular

W.

r.plocement

of t

type01replac.....,,'

pan

worrantyorguaranty

the

quality and suitabHity of such

.....

pons

hove

10,11,12

Sams

Mr.in

been

pon

7

15

6,7

6

does

compiled

listed.

SAFETY PRECAUTIONS

See page

Photos

Expansion Interface Board 4,8,13,17 Safety Precautions 9 Schematics

Expansion Interface Board 2,19,20,21

Power Supply 3,18 Schematic Notes 15 Troubleshooting 14,15

& Co., Inc•

no1 Reproduction

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120

20

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19

28

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FOOATA

27

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26

XTDS

25

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ro]

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S1174lS367AJ1

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13 12

11

10

9

1

4

7

8

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4A

IY

4B 4Y

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2B

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INPUTS

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INPUTS

1

1\

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12

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10

OUTPUTS

IIC7S4S2P

218

DRIVER

TOP

5

6

7

8

VIEW

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IYl

lYO

GND

S1174lS244"

4----=..:.~18

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m.

231.

2«.

245

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S"74LSlSS"

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8 B

A

ZJ9

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lYO

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SIDE

B A

A

CR2

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VIEW

20

19

13

II

vee

BCE

01.

FROTVIEW

16

5

MISCELLANEOUS ADJUSTMENTS

PIN NO.

1 3

4 P 5

6

8

9

IC

Zl

L L L

2 P

P P

P

7

H H H H H

P P

10

P

11 12 P

13 P P 14 P

H

15

L L

16

12V AND

NOTE:

Connect (Z20).

Connect (Z21).

IC IC

12

Z3

P P P

P

P P P

P P

P

P P P P

P

H H

P

P P P P

P

P P

P

P P P

P

H H

H

L L

SV

ADJUSTMENT

Perform

Adjust

12V

the

inputofa DC

the

inputofa DC

the5VAdjust

adjustment

12V

Adjust

before5Vadjustment.

voltmetertopin3of

Control

voltmetertopin3of

Control

(R7)

(R8)

for

LOGIC CHART

IC IC IC IC

IC

Z4 Z5 Z6

L L L L L L

P P P P P P P P P P

P

H H

H

H H H

P P P

P P

H H

L L L L

Z7 Z8

P P P P P P P P P

P P P P

H H H

H H

P P

P P P P

P P P

H H H

Regulator

for

11.9V.

Regulator

5.0V.

IC IC

Z10

Z9

L

P P P P

P

H H

H

P P

P

P P

P

H

L L

L

IC

Z11

L

P

P P

H

P P

P P P

P

H H

IC

Z12 L

P

P P P P

P P

H H H

P

P P P P

L

IC

Z13 Z14

L L

P P

P

P P

P

H

P

P P

H

L L

IC

NO.

Z15

L L

1

P

2

P P

3 4 P P

P P L

5

P

6 7 P

H H

8

H

9

P P

10

P P

11

12

P P P L

13 14 P

H H

15 16 L L

NOTE:

Logic On,nokeys

Logic

Probe L=Low H =

High

P=

Pulse

*=

Open

Logic

(No readings

(1)

Z16 Z17

P

P L

probe

Display

light

IC

P

H H

P

readings

pressed,

On)

not

taken.

IC

IC IC

Z18 Z19 Z20

H H

P

H

L

H L

L

H P

P

H L

L

H

taken

unless

IC IC

121

(1 ) (1 )

H

*

H

*

H L

*

H

P

*

P

P L L

IC IC

Z22 Z23

P L

L

P

L

*

H P L L

P L P L L

L P P P P

*

P P P

*

with

computer

otherwise

turned

noted.

IC

Z24 Z25

L

P

P P

P

P P P H

P

L L

L H L

P

P L

P P P

p

P

H H

IC

H H

P L P

H

P L

H

P

L

H

IC

Z26

P H H

L

H P

L

H

L

H H

H

IC

Z27

P H

H

P L

P P P L P

P

H

P

H H

IC

Z28

H

L

H

L P

P P P P

P

6

LOGIC CHART (Continued)

NO.

IC

·Z29

IC IC IC

Z30

1 L L 2

P

*

P

3

4 P

5

6 P

7

P

'P

P

P P P P

P P P

L P L

8 P H P

9 P P 10

L P

11

P H

12

P

*

13

P

14 15 16

17

18 19 20

PIN NO.

1 2

3

4

L P P

P H

P

P P

H

H H

IC

Z42

NO.

21

L

H

22

L 23

H

24

Z31

Z32 Z33

P

L P

P H H L H

P

P L H

P L

P H P P P L H

P

H L H P P

P H

IC

Z42

NO. H 1

H

2 P P P

L

3 P L P

P 4

IC IC

Z34

L

L P

*

H L P

*

L

*

P

L P

L

*

H

L P

L P P

H H

L P H

L H

IC

Z43

L

P P

IC

Z44

L

IC IC

IC

l35

Z36 Z37

P

P P

P

P P

P

P P

P

L

L P

P

L P

P P

L L H H

IC IC IC

Z45

Z46

H

L

H

*

P

H

IC IC IC

Z38

(1)

L

*

P

P H P H

L H H L P

P H H H P

*

L P P H H

Z47

L L L H P P

IC IC IC

Z48

H

P

Z39

Z40

P P H P P P L H P

P L

H L L H P L H P L

H H

H H P P H H

Z49

Z50

H

H H P P P P P P P P

IC

Z41

P L

* *

*

L

IC

Z51

P

(')

en

(')

en

CN

•

:t>

5 P

P

6

7

8

9 10

11

12 13

14

*

15 16

L

17 18

H

19

20

L

NOTE:

Logic On, no keys pressed,

Logic

Probe Display

L

= Low * =Open (No

= High

H P

=Pulse

25 26 27

*

28

*

29

*

30

*

31

*

32 L

*

33 H

*

34

L

35

36

L

37 38

H

39

40

probe readings taken

(1)

H H L 7

L 8 H

L 9

L

H

L

H

Logic

DISASSEMBLY INSTRUCTIONS

5 P 6 P P

L

*

10

*

11

P L P

12

P P

13

*

14

H

15 16

17 18 19

20

with

unless

otherwise

light

readings

On)

not

P P

P P L P

L

P P P P

L P L H H

computer

noted.

taken.

P H P P

L P P P P

P P P

P P L

turned

P

L

H

L

L P

P

L P

P

H L P P L H

*

P P

P

H H

L H H

L P P L P P

P L P

L P H

P

H H P

P

p.

H

L H

H

P

H

H H

P

L

*

•

* *

* * * *

*

* * *

H H

P P

P L

*

•

*

H

CABINET REMOVAL

Remove six bottom service.

screws

from unit. All

from

cabinet

components

bottom.

are

Remove cabinet

now

accessible

for

7

EXPANSION

INTERFACE

BOARD GridTrace

LOCATION GUIDE

Cl

C2 C3 C4

C5

C6 C7

C8

C9

Cl0 Cll C12 C13

C14

C15

C16

C17

C18 C19 C20 C21 C22

C23

C24 C25 C26 C27

C28

C29 C30 C31 C32 C33 C34 C35

C36

C37 C38 C39 C40

C41

C42

C43

C44

C45

C46

C47

C48

C49 C50 C51 C52

C53

C54 C55 C56 C57 C58 C59 C60 C61 C62 C63 C64 C65

C66 C67 C68 C69 C70 C71

cn

C-8 C-9 C-ll C-12

C-13

C-14 C-15 C-17 F-8 E-9 F-l0 F-ll E-ll F-12

F-13

F-14 E-15 F-15 F-16 F-17

F-8

F-9 F-ll F-12 F-13 F-14 F-15 F-17 H-8

H-9 H-l0

H-l1 H-ll

H-12 H-13

H-14 H-14 H-15 H-16 H-17 A-I B-3 C-2 0-1

0-5

C-7

0-7

E-7

G-6

J-2

K-6

L-5

0-3

K-9 N-8 P-5

P-8 K-ll K-15

N-15

B-17 C-17

K-17

M-18

0-18 Q-18

B-19

0-19

C-21 0-22 0-23

1-22

L-20

EXPANSION

C74 C75 C76

cn

C78 C79 CRI CR2 CR3 CR4

J6 J7

1

A

B

c

D

G

H

K L

M

N

o

p

Q

R

1

INTERFACE

M-21 N-22 C-25 Kl

G-25

1-25

L

-24 B-5 Q-3 K-16

K-8

A-16

A-13

J8

J9 Ql

Q2

Q3 Rl R2 R3 R4 R5 R6

2

3

BOARD

4

A

HowordWSoms

A-II

Q-l

B-7

G-4 RIO

N-4 N-5 C-4 0-3

E-6 H-5 R

1-2

I

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R7 R8 R9

R11

R12

R13

R14

R15 R17

R

16 18

(§jli1Ji¥i'W

J-l

K-1

K-2

M-3

0-3

P-3

Q-4

K-5

0-5

I

-9

R19 R20 R21 R22 R23 R24 R25 R26 R27 R2B R29 R30

Photo

1-9

K-10 L-14

A-18

C-18

A-18 C-18 E-19 H-19 K-20 0-24 E-24

R31

R32

R33

R34

R35

Yl

ZI Z2 Z3 Z4 Z5 Z6

E-24 E-24 F-24 G-23 K-4 C-l 0-9 0-10

0-11

0-12

0-13

0-14

Z7

Z8 Z9

Z10

ZII Z12

Z13

Z14

Z15

Z16

Z17

Z18

18

0-16 0-17 G-8

G-l0

G-l1 G-12

G-13

G-14 G-15 G-17 A-2 B-4

19

Z19 Z20

Z21

Z22

Z23

Z24 Z25 Z26

Z27

Z28 Z29 Z30

221

0-4 J-3

Q-4 Z33 O-{i Z34

F-6 H-{i Z36 J-6 L-{i J-9 L-9 J-12 L-12

Z31 Z32

Z35 Z37

Z38

Z39 Z40 Z41

23

1

24

25

J

1

26 27

I

23124-125126127

J-16 L-16

A-19 C-19 E-19 G-19 L-19 N-19

P-19

R-18 C-22

Z42 Z43 L-21 Z44

Z45

Z46 B-25 Z47 Z48 Z49 Z50

Z51

EXPANSION

28

A

B

c

D

E

F

G H

J

M

N

o

p

Q

R

28

F-22 0-21

0-23

0-25

F-25 H-25 J-25

L-25

INTERFACE

BOARD

::D

3::1>

2

0

m0

,...~

-:I>

""0

m"

<-4

~::D

_0

-0,

o

8

13

SAFETY PRECAUTIONS

1.

Useanisolation transformer for servicing.

2.

MaintainACline voltage at rated input.

3.

RemoveACpower from the of

typicalESdevices are integrated

4.

Use extreme caution when handling the printed static

electricity. Drain

Iy available discharging

5.

Use a grounded·tip, low voltage soldering iron.

6.

Useanisolation (times

7.

Do

not remove or install boards, floppy disk drives, printers, or other peripherals

8.

Do

not use freon·propelled sprays. These can generate electrical charges

9.

Periodically examine theACpower cord for damaged or cracked insulation.

10.

The

computer

vents.

11.

Instructions cabinet. This could cause shockorequipment damage.

12.

Never expose the near possible water sources.

system cabinet is equipped

should be given, especially to children, that

computer

off

any

wrist

10)

probe on scope.

system to water. If exposedtowater turn the

system before servicingorinstalling

circuits

electrostatic

strap device. This should be removed prior to applying power to the

and

semiconductor

circuit

boards. Some

charge on

with

your

body by

ventstoprevent heat build·up. Never block, cover, or

objects

electrostatically

'chip'

components.

semiconductor

touching

should not be dropped or pushed

a known earth ground. Weara commercial·

with

sufficienttodamage

unit

Off.Donot place the computer system .:....

sensitive devices. Examples

devices can be damaged easily by

computer system AC power On.

unit

under test.

semiconductor

obstruct

into

the ventsofthe

devices.

these

(")

en

(")

en

W

""

13.

Never leave the from AC

14.

Do

not allow anything to rest onACpower cord.

15.

UnplugACpower cord from outlet before cleaning

16.

Never use liquids or aerosols directly on the

cabinet. Make sure the computer system is disconnected from the AC power line.

outlet

computer

during

system unattended or plugged

lightning

storms.

computer

into

the AC

computer

system.

system. Spray on

outlet

for

long periodsoftime. Remove AC plug

cloth

and then applytothe computer system

::Il

3:>

2

0

men

r-:I:

->

r-O

m",

<-4

~::Il

_en

-cio

o

9

~

PARTS LIST AND DESCRIPTION

When ordering parts, state Model, Part Number, and Description

SEMICONDUCTORS (Select replacement transistor for best results)

ITEM

No.

m1

CR2 CR3

CR4

Ql,2 Q3

Zl

thru

Z16 Z17 Z18 Z19

Z20,21 Z22 SN74LS90N Z23,24 Z25,26 Z27 SN74LS32N

Z28 Z19 Z30 Z31 Z32

Z33 Z34

Z35,36 Z38

Z39

TYPE

No.

lN4148 BR-82D MDA202

.5M5.1

ZS3

lN5231 T4446

lN4735 E1600

MJE2955 MPS3904

2N3904

8041016

MK4116

SN74LSOON

MC75452P

MC14049UB

4049B

MCl723CP 3100001

MC14518B GE-4518

SN74LS74AN

SN74LSOON

SN74LS244N 74LS244

SN74LS243N

SN74LS244N

SN74LS04N

SN74LS123N 74LS123

DM7416N

SN74LS157N SN74LS243N

SN74LS155N NTE74LS 155 ECG74LS 155

4800002

4800023

4800022

4800021

4822001

3102006 3106002

3102015 3102014

3102006

3102008

3102020

MFGR.

PART

No.

GENERAL ELECTRIC NTE

PART No.

GE-514 GE-167 NTE167 GE-167 GElD-5.1 GEZD-5.1 NTE5010A

GEZD-6.2 GE-56

GE-123AP NTE123AP GE-123AP

74LSOO GE-4049

GE-4049 GEIC-260

74LS90 74LS74A

74LS32 74LSOO

74LS244

74LS04

GE-7416

74LS157 NTE74LS 157

NEW·TONE PHILIPS

PART No. PART No. NTE519 NTE167

NTE5010A

NTE137A NTE183 NTE123AP

NTE2117 NTE74LSOO NTE75452B ECG75452B NTE4049 NTE4049

NTE923D NTE74LS90 NTE4518B NTE74LS74A NTE74LS32

NTE74LSOO NTE74LS244 NTE74LS243

NTE74LS244

NTE74LS04

NTE74LS123

NTE7416

NTE74LS243

REPLACEMENT

ECG

ECG519 ECG167 ECG167 ECG5010A ECG5010A

ECG137A ECG183

ECG123AP ECG123AP

ECG2117 ECG74LSOO

ECG4049 ECG4049

ECG923D ECG74LS90 ECG4518B SK4518B

ECG74LS74A ECG74LS32

ECG74LSOO

ECG74LS244 ECG74LS243 ECG74LS244 ECG74LS04

ECG74LS123 ECG7416

ECG74LS 157 SK74LS 157 ECG74LS243

DATA

RCA

PART No.

SK3100/519

SK36471167 SK36471167

SK5A1/5010A

SK6V2l137A SK3189A1183

SK3854/123AP SK3854/123AP

SK74LSOO SK4049UB

SK4049UB

SK3165/923D

SK74LS90 SK74LS74A

SK74LS32 SK74LSOO

SK74LS244

SK74LS243 SK74LS244 SK74LS04

SK74LS123

SK7416

SK74LS243 SK74LS 155

WORKMAN

PART

No.

WEP925/519 WEP1052/167 WEPI

052/167

WEP1411/5010 WEP1411/5010

WEP1154/137 WEP748/183

WEP

736/1 23A

WEP736/123A

WEP2331

I

9230

ZENITH

PART

No.

103-131 212-Z9001 212-Z9001

103-279-10 103-279-10

103-Z9008

121-Z9000A

HE-443-904 HE-443-728 HE-443-74 221-Z9074

221-Z9074 221-Z9020 HE

-443-737

HE-443-730 HE-443-875

HE-443-728 HE

-443-791 HE-443-839 HE-443-791 HE-443-755

HE-443-942 HE-443-73 HE-443-799

HE-443-839

HE-443-782

PARTS LIST AND DESCRIPTION (Continued)

When ordering parts, state Model, Part Number, and Description

SEMICONDUCTORS (Select replacement

ITEM TYPE MFGR.

No. No. PART No.

139N

Z40 Z41 Z42 Z43 SN74LS30N Z44,45

Z46 Z47 74LS 175PC Z48 Z49 SN74LS367N-4 Z50,51

CAPACITORS

ITEM

No.

SN74LS DM7416N FD17718-01

SN74LS244N

SN74LS20N

SN74LS273N

SN74LS240N

RATING

Items

3102013

3102023 3102024

not

lIsted

PART

MFGR.

ere

normelIyevelleble

No.

transistor

GENERAL ELECTRIC

PART No.

74LS 139

~-7416

74LS30 74LS244

74LS20 74LS 175 NTE74LS 175 74LS273 NTE74LS273 ECG74LS273

74LS367A NTE74 LS367

74LS240

Iii

ITEM

No.

for

best results)

NEW·TONE

NTE

PART No. PART No.

NTE74LS 139 ECG74LS 139 NTE7416

NTE74LS30 ECG74LS30 NTE74LS244 ECG74LS244

NTE74LS20

NTE74LS240

et

locel

distrIbutors.

RATING

ECG7416 SK7416

ECG74LS20 ECG74LS175 SK74LS 175

ECG74LS367 SK74LS367 ECG74LS240

PHILIPS

ECG

REPLACEMENT DATA

RCA WORKMAN ZENITH

PART No.

SK74LS139

SK74LS30 SK74LS244

SK74LS20 SK74LS273 SK74LS240

MFGR.

PART

No.

PART No.

HE-443-73

HE-443-732 HE-443-791

HE-443-798 HE

-443-752

HE-443-805

HE-443-857

HE-443-754

....

C43

10pF N750 50V

II

131\31

09·SHl

I

1300W

>t:)"HS OIO"H

PARTS LIST AND DESCRIPTION (Continued)

When ordering parts, state Model, Part Number, and Description

CONTROLS (All wattages

R7

R8

ITEM

NO.

FUNCTION RESISTANCE

+12V Adj +5V

Adj

ust

Y2

watt,

1000 4750019 1000 4750019

RESISTORS (Power and Special)

R18 R19 R26 R27 R35

(1) (2)

ITEM

No.

ContaIns ContaIns

ResIstor ResIstor ResIstor

Res Is

5.6

5%

four

4700,

four

33,

tor

3'11

Network

Network Network Network

WW

10%.

RATING

(I)

(2)

or

less, unless listed)

MFGR.

PART NO.

MFGR.

PART No.

4717003

NOTES

REPLACEMENT DATA

NEW·TONE

PART No.

WORKMAN

PART No.

MISCELLANEOUS

ITEM

No.

Kl

Prl

SI

Yl

Z37

(I)

Relay

Power Suppl y SwItch Crystal Del ayLIne P.C.

NumberonunIt.

PART

Board

NAME

MFGR.

PART

No.

FRL

-414D005/04CT

(1)

4000004

DOU-4-7835<1 ) 8709001

Motor

AC

4.0~z

Expans

CABINET & CABINET PARTS (When ordering

PART

No.

CabInet, CabInet,

ITEM

Top

Bo1'tom

Control,

Power

On-Off

Ion

specify

Cover,

Power

Compartment

ExpansIon

NOTES

5V42Ohms

Interface

model, chassis & color)

ITEM

Supply

Compartment

PART

No.

12

EXPANSION

INTERFACE

BOARD GridTrace

LOCATION GUIDE

Cl

C2 C3 C4

C5

C6 C7

C8

C9

Cl0 Cll C12 C13

C14

C15

C16

C17

C18 C19 C20 C21 C22

C23

C24 C25 C26 C27

C28

C29 C30 C31 C32 C33 C34 C35

C36

C37 C38 C39 C40

C41

C42

C43

C44

C45

C46

C47

C48

C49 C50 C51 C52

C53

C54 C55 C56 C57 C58 C59 C60 C61 C62 C63 C64 C65

C66 C67 C68 C69 C70 C71

cn

C-8 C-9 C-ll C-12

C-13

C-14 C-15 C-17 F-8 E-9 F-l0 F-ll E-ll F-12

F-13

F-14 E-15 F-15 F-16 F-17

F-8

F-9 F-ll F-12 F-13 F-14 F-15 F-17 H-8

H-9 H-l0

H-l1 H-ll

H-12 H-13

H-14 H-14 H-15 H-16 H-17 A-I B-3 C-2 0-1

0-5

C-7

0-7

E-7

G-6

J-2

K-6

L-5

0-3

K-9 N-8 P-5

P-8 K-ll K-15

N-15

B-17 C-17

K-17

M-18

0-18 Q-18

B-19

0-19

C-21 0-22 0-23

1-22

L-20

EXPANSION

C74 C75 C76

cn

C78 C79 CRI CR2 CR3 CR4

J6 J7

1

A

B

c

D

G

H

K L

M

N

o

p

Q

R

1

INTERFACE

M-21 N-22 C-25 Kl

G-25

1-25

L

-24 B-5 Q-3 K-16

K-8

A-16

A-13

J8

J9 Ql

Q2

Q3 Rl R2 R3 R4 R5 R6

2

3

BOARD

4

A

HowordWSoms

A-II

Q-l

B-7

G-4 RIO

N-4 N-5 C-4 0-3

E-6 H-5 R

1-2

I

-4

R7 R8 R9

R11

R12

R13

R14

R15 R17

R

16 18

(§jli1Ji¥i'W

J-l

K-1

K-2

M-3

0-3

P-3

Q-4

K-5

0-5

I

-9

R19 R20 R21 R22 R23 R24 R25 R26 R27 R2B R29 R30

Photo

1-9

K-10 L-14

A-18

C-18

A-18 C-18 E-19 H-19 K-20 0-24 E-24

R31

R32

R33

R34

R35

Yl

ZI Z2 Z3 Z4 Z5 Z6

E-24 E-24 F-24 G-23 K-4 C-l 0-9 0-10

0-11

0-12

0-13

0-14

Z7

Z8 Z9

Z10

ZII Z12

Z13

Z14

Z15

Z16

Z17

Z18

18

0-16 0-17 G-8

G-l0

G-l1 G-12

G-13

G-14 G-15 G-17 A-2 B-4

19

Z19 Z20

Z21

Z22

Z23

Z24 Z25 Z26

Z27

Z28 Z29 Z30

221

0-4 J-3

Q-4 Z33 O-{i Z34

F-6 H-{i Z36 J-6 L-{i J-9 L-9 J-12 L-12

Z31 Z32

Z35 Z37

Z38

Z39 Z40 Z41

23

1

24

25

J

1

26 27

I

23124-125126127

J-16 L-16 A-19 C-19 E-19 G-19 L-19 N-19

P-19

R-18 C-22

Z42 Z43 L-21 Z44

Z45

Z46 B-25 Z47 Z48 Z49 Z50

Z51

EXPANSION

28

A

B

c

D

E

F

G H

J

M

N

o

p

Q

R

28

F-22 0-21

0-23

0-25

F-25 H-25 J-25

L-25

INTERFACE

BOARD

::D

3::1>

2

0

m0

,...~

-:I>

""0

m"

<-4

~::D

_0

-0,

o

8

13

POWER SUPPLY

TROUBLESHOOTING

Disconnect the Power Supply terface Board and check for 19.7VAC between pin 1 and pin 3ofConnector J9 and 23.6V between pin 2and pin 4ofConnector

J9. If the voltages are missing, check the cable and connections at the Connector J9 and check for open AC power cord. If the voltages are present, reconnect the Power Supply to the Expansion Interface Board and turn the Expansion Interface Board. Check RegulatorIC(Z21),

-

5.OV

at the anodeofZener Diode

missing, check the Power Switch (Sl).

If

5.OV

is missing, check associated Regulator Drive Transistor (03) and pins 2 thru 13ofIC justmentofthe5VAdjust

If the 11.9V is missing, check the voltages and associated thru7,10,11and 13ofIC Z20. If the 11.9V source is incorrect, check the adjustmentofthe

If and check for a possible short to ground.

LINE PRINTER

If the Line Printer Connector (J4) is run the following Basic program and use the ceduretocheck the printer interface circuits. NOTE:Donot connect a printertoConnector J4.

10 20 30 40 SO 60 70

Check for pulses at pin 1ofthe Tri-State pulses are missing, check MUX (Multiplexer) IC substitution. one at a time, pins2,4,

that appears on the to determine the correct number X should equal

Pin 2ofZ49 Pin 4ofZ49 Pin 6ofZ49X=191 Pin 10ofZ49 X = 127

If any number is incorrect, check IC Check check

12,15,16

Z48, check IC Z48 by

pin11of pulses at pin 4ofFlip/FlopIC(Z33).

a width

correct, check Capacitor C61, Resistors check Flip/FlopICZ33 by

Z21. If the

the

5.OV

is missing, check Resistor

FOR Y = 1 TO POKE 14312,0 POKE 14312,255 X = PEEK(14312) NEXT Y PRINT"X= "; X GOTO

10

for

the waveform shown in Figure 2 at pins2,5,6,9,

and19of IC Z48. If any waveform is

IC Z48, check IC Z39 by

of

2!J.s.

11.9V at pin 3ofRegulator IC (Z20) and

with

Regulator Output Transistor (02) and

5.OV

with

Regulator Output Transistor (01) and pins 2

SO

Check the operationofIC Z49 by grounding,

Monitor

255

when none of the pins are grounded.

X=239 X=223

pulses at pin11of

substitution.Ifpulses are missing at

If the pulses are missingorthe

(PT1)

from the Expansion In-

On

for

5.OV

at pin 3

CR3.Ifall voltages are

the

voltages and components

7,10,11

source is incorrect, check the ad-

Control

6 and 10 and observe the number X

substitution.

(R8).

components

12V

Adjust Control (R7j).

R21,

Zener Diode CR3

not

operating, type and

following

BufferIC(Z49).

screen. Use the following chart

for

each pin. The number

Z49bysubstitution.

the Flip/FlopIC(Z48) and

missing

substitution.

The pulses should have

R23

and

(Z39)

at IC

Check for

width

is in-

R24

and

pro-

and

of

by

Figure 2

DISK DRIVE

If the Disk Drive Port (J5) is clock

signal at pin24of clockisoff Capacitors C43 and C44 and ResistorsRland clock 3ofFlip/Flop IC check IC Z25 by pin3,check the waveform at pin14of the waveform is present at pin tion.Ifthe waveform is missing at pin substitution. and ResistorsR1and 24ofIC Z42, type and run the following Basic program and check IC

(Z39).

10

FORX=14304TO14316 STEP 4

20

Y +

30

NEXT X

40

GOTO

If pulses are missing at anyofthe pins specified onICZ39,

check IC Z39 by

The Disk Drive

Drive should be On when the above program is running. If the Disk Drive

at pin 5ofFlip/Flop IC

running). If the by

If

substitution.Ifthe

for

pulses at pin 9ofIC Z41.Ifpulses are missing at pin check IC Z39 by check Capacitor C62, Resistors Z33 by substituion.ICZ33 is a

Drive running for about 3 seconds

at pin 9ofIC Z33.

If the LED on the Disk Drive is not On when the program is running, check for a High IC

(Z47)

Z47 for Drive 2orpin15ofICZ47 for Drive3.If the reading

is correct, checkICZ41bysubstitution. correct, check IC

If the Disk Drive is not reading, writing or the Head Stepping Motor check ICs Z51) by

The operationofpins

by running the following Basic program and

valueofthe number X that appears on the

when a jumper is connected from groundtooneofthe pins.

frequency, check the 4.0MHz Crystal (Yl),

signal is missing at pin

(Z25).

substitution.

Check Crystal

for

pulses at pins4,5,7,9 and11of

PEEK(X):

is not running and the above

POKE X,255

10

substitution.

Motor

logic

substitution.

for

Drive0,pin 7 of IC

Z47bysubstitution.

Z32,

Z34,

substitution.

not

operating, check

the Disk Controller IC

24,

check the waveform at pin

If the waveform is present at pin

If the waveform is missing at

Counter IC

14,

check IC Z22 by substitu-

Yl,

R2.Ifthe

and the LED on the frontofthe Disk

is not running, check the

(Z33)

for

reading at pin 5 is High, check IC

logic

Z42

34,35and36ofICZ42

a High (while the program is

reading at pin 5 is Low, check

If pulses are present at pin

logic

reading at pin 2ofFlip/Flop Z47

and Tri-State

14,

Capacitors C43 and C44

clock

signal is good at pin

Mux (Multiplexer)

R24

and

R25

timer

that keeps the Disk

after

a pulse is received

for Drive1,pin10of

If the reading is in-

circuit

Buffer

5V 5ms

OV

for

a 1MHz

(Z42).

If the

R2.

If the

3,

(Z22).

checkICZ19 by

logic

reading

Z41

and check IC

IC

checks are good,

ICs

(ZSO

and

can be checked

noting

the

Monitor

screen

If

9, 9,

14

TROUBLESHOOTING (Continued)

NOTE: Turn

from Drive Connector (J3).

10

POKE 14304,255: X - PEEK(14316)

20

PRINT"X = ";X

30

FOR T = 1TO 400: NEXT T

40

GOTO

Pin34of Pin35of Pin36of Pins

Off

the Computer and disconnect all

10

Z42 grounded X= 4 Z42

grounded X = 2

Z42

34,35and36not grounded X= 0

grounded X =

64

disk

drives

LINE DEFINITIONS

AO

Thru A15 Address Lines

BAO

Thru BA

BOO

Thru BD7 Buffered Data Lines

BRD BWR Buffered Write CASSIN Cassette Input CASSOUT _ Cassette Output CLK Clock CLR Clear DO

Thru07'" DIR SEL Direction Select DSO

Thru EN1, EN2 Enable IN INT Interrupt INDEX Index Pulse INTRa INTAK Interrupt Acknowledge M32 Column Address Strobe M48 Column Address Strobe for 48K Memory MAO MOO

15

DS3

Thru MA6 MemoryAddress Lines Thru MD7 MemoryData Lines

Buffered Address Lines

Buffered

Interrupt Request

for

Read

Data Lines

Data Select

Input

32K Memory

CASSETIE

If

Motor

pulses at pins 3 and 4ofIC Z32. If pulses are

3,

are present at pin 3 and missing at pin 4ofIC Z32, checkIC

Z32 by

If pulses are present at pin 4ofIC Z32, check reading that toggles between Low and High at pins 1and 3 of check IC pin 1and wrong on pin 3ofIC tion. If the RelayK1and Diode

MOTOR Disk MRAS Memory Addess Signal OUT RAS RD

RD STEP STROBE DataStrobe SYSRES System Reset TEST TRK WAIT , Wait WR WR WR 32K Dynamic RAM 37EO 37E4 37E6 37E8 48K , Dynamic RAM

Control Relay

check Mux (Multiplexer) IC

substitution.

Driver IC

DATA Read Data

00

DATA Write Data

PROT Write Protect

(Z18).

Z17bysubstitution.

logic

............................•.............

RD WR WR

RD

Memory Address Signal to Interrupt Logic

(K1)

is not operating, check for

(Z39)

by substituion.Ifpulses

If the

logic

reading on pin 1 is incorrect,

If the

logic

reading is good at pin 3ofIC Z18, check

CR1.

Memory Address SignaltoPrinter Logic

Z18, checkICZ18 by substitu-

"

RIW

Head Movement Pulse

Memory Address Signal Memory Address Signal

missing

reading is good on

MotorOnLine

Row Address Strobe

Clocking

at pin

foralogic

Output

Read

Pulse

Test

Track 0

Write

Any Bar above any alphabetical or numerical

SCHEMATIC NOTES

--Circuitry

- - -

Circuitry

e See parts

~

Ground

nm

Chassis

'9 Common tie point

Waveforms and voltages taken from ground, unless noted

Voltages, Waveforms and Logic probe readings taken with

Waveforms taken

Time in p.sec. per cm, given with

not used in some versions used in some versions

list

otherwise.

computer noted.

switch coupling on 0 reference voltage waveforms. SwitchtoAC input to view waveforms when necessary. Each waveform is 7 cm. reference voltage given at the form.

each waveform.

turned On, no keys pressed, unless otherwise

with

triggered scope and SweepfTime

in Calibrate position, scope input set for

afterDCreference is measured

bottom

pop

width

lineofeach wave·

reading at the end of

combination

DC

with

DC

indicates line active in a low

Item numbers in rectangles appear in the alignment/ad-

justment Supply voltages maintained as shown at input. Voltages measured with digital meter,nosignal. Controls adjusted for normal operation. Terminal Capacitors are50voltsorless, 10% unless noted. Electrolytic capacitors are50volts or less, 20% unless

noted. Resistors are Value in ( ) used in some versions. Measurements

Logic Probe Display L=Low H = High P= Pulse

*= Open (No

(1)

Logic readings not taken.

instructions.

identification

Y2Worless, 5% unless noted.

light

with

may

switching

On)

(0)

state.

not

be foundonunit.

as shown, unless noted.

15

Ie

PINOUTS & TERMINAL GUIDES

S1114LS9Oll

NC

Real

4

NC

~

Yet

6

R9ill

R9(11

7

122

COU

1IR

TOP

lEW

1 4 6 8

10 121416 18

::::::::::::::::::::

I 3~7 9II13I~1719

I 3~7 9 II

::::::::::::::::::::

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,

7092, Indianapolis, Indiana 46206 U.S.A.

ITT

Radio Shack TRS-80, TRS-80 Model I, 26-1001, 26-1201, 26-1140 Technical Service Data

Specifications and Main Features

Frequently Asked Questions

User Manual

MONITOR