Commodore 1701, 1702 Service Manual

SERVICE

MANUAL

MODEL

1701/1702

MONITOR

Preliminary

OCT.

1984

PN-314004-01

Commodore Business Machines, Inc.

1200

Wilson Drive,

West

Chester, Pennsylvania

19380

U.S.A.

Commodore makes no expressed

or

implied

war-

ranties

with

regard

to

the

information

contained
herein. The information is made available solely on
an as is basis, and

the

entire risk as

to

quality

and

accuracy is

with

the

user. Commodore shall

not

be

liable

for

any consequential or incidental damages

in connection

with

the

use

of

the

information

con-

tained herein. The listing

of

any available replace-

ment

part herein does

not

constitute

in

any

case

a recommendation,

warranty

or

guaranty

as

to

quality

or

suitability

of

such replacement part.

Reproduction or use

without

expressed permission,

of

editorial

or

pictorial

content,

in any

matter

is

prohibited.

This manual contains copyrighted and proprietary

information.

No part

of

this

publication may

be

reproduced, stored in a retrieval

system,

or

transmitted

in any

form

or

by

any

means, electronic, mechanical,

photocopying, recording or otherwise,

without

the

prior

written

permis-

sion

of

Commodore Electronics Limited.

Copyright © 1984

by

Commodore Electronics Limited.

All

rights reserved.

CONTENTS

Title

Page

SPECIFICATIONS

1

SAFETY PRECAUTIONS

.........................................................................................

2

ADJUSTMENTS

PURITY

......................................................................................................

4

CONVERGENCE

...........................................................................................

5

WHITE BALANCE

........................................................................................

5

B1

VOLTAGE, FOCUS, VERT. & HOR. ADJ.

...................................................

6

SUB TINT, SUB CONTRAST, COLOR SYNC,

3.58

MHz TRAP

...........................

7

BLOCK DIAGRAM

.................................................................................................

8

CIRCUIT NOTES

VIDEO CIRCUIT

...........................................................................................

9

AUDIO CIRCUIT

..........................................................................................

10

COLOR DEMODULATION CIRCUIT

................................................................

11

CHROMA OUTPUT CIRCUIT

............

..........................

..............

........

.............

12

CONTROL CIRCUIT

......................................................................................

13

H.

OSC., V. OSC. & V. OUT CIRCUIT

............................................................

14

HORIZONTAL OUTPUT CIRCUIT

...................................................................

15

POWER

CIRCUIT

.........................................................................................

16

TROUBLESHOOTING GUIDE

NO

RASTER,

NO

SOUND

(B

1

NORMAL)

........................................................

17

NO

RASTER,

NO

SOUND

(B1

ABNORMAL)

....................................

................

18

NO

RASTER, NORMAL SOUND

.....................................................................

19

NO

SOUND, NORMAL PICTURE

....................................................................

19

SINGLE HORIZONTAL LINE, NORMAL SOUND

................................................

20

IMPROPER

HORIZONTAL

OR

VERTICAL SYNC

...............................................

22

iii

CONTENTS

(Continued)

Title

Page

1701 PARTS LIST

..

...............................................................................................

23

1701 BOARD

LAyOUT.........

.................................................................................

30

1701 SCHEMATIC NOTES

.....................................................................................

31

1701 SCHEMATIC

................................................................................................

31

1702

MODEL IDENTIFICATION

........................................

........................

...............

32

1702

PARTS LIST

.................................................................................................

33

1702

BOARD LAYOUT

..........................................................................................

40

1702

SCHEMATIC NOTES

.....................................................................................

41

1702

SCHEMATIC

...........................................

.....

................................................

41

1702T

BOARD LAYOUT

........................................................................................

42

1702T

UNIQUE PARTS

..........................................................................................

43

1702T

SCHEMATIC

..............................................................................................

43

iv

GENERAL DESCRIPTION

C1701/C1702

COLOR

MONITORS

PRODUCT

SPECIFICATION

The C1701 and

C1702

are quality, high resolution color monitors, designed

to

maximize

the

video

capabilities

of

your

Commodore Computer. They give you a superior color picture

that

enhances

your

computing

experience and are completely compatible

with

all Commodore equipment.

SCREEN SIZE

13

Inch (screen measured diagonally). NTSC color standard

DISPLAY

40

Columns x

25

lines

RESOLUTION

1000

Characters per screen

CONTROLS

Color,

tint,

brightness, contrast, volume, vertical hold and horizontal hold

AUDIO

Built-in audio amplifier and speaker

INPUTS

Chrominance, luminance, composite video and audio

OTHER FEATURES

Video cassette recorder compatible

(1

V p-p,

75

Ohms)

COMPUTERS

Commodore

64,

VIC

20,

Plus/4 and

C16

POWER REQUIREMENTS

120

Volts,

60

Hz,

0.85

Amps

POWER CONSUMPTION

87

Watts

All specifications subject

to

change

without

notice.

1

SAFETY

PRECAUTIONS

1. This

product

contains special designed circuits and

components

that

were designed

for

safety

purposes.

For continued

protection,

changes should

not

be made

to

the

original design unless authorized

in

writing

by

the

manufacturer. Replacement parts

must

be identical

to

those used in

the

original

circuits. Service should

be

performed

by

qualified personnel only.

2. Alterations

to

the

design or

circuitry

of

this

receiver should

not

be made.

Any

design alterations

or

additions

will

void

the

manufactuer's

warranty

and

will

further

relieve the

manufacturer

of

responsibility

for

personal injury or

property

damage resulting

therefrom.

3.

Many

electrical and mechanical parts in MONITOR sets have special safety-related characteristics.

These characteristics are

often

not

evident

from

visual inspection nor can the protection afforded

by

them

necessarily

be

obtained

by

using replacement components rated for higher voltage,

watt-

age, etc. Replacement parts

which

have these special

safety

characteristics are identified in

the

parts list

of

this

service manual. Electrical

components

having such features are identified

by

shading on the schematics and by

(*)

on the parts list in this service manual. The use

of

a substitute

replacement

which

does

not

have

the

same

safety

characteristics

as

the

recommended

replacement part

shown

in

the

parts list

may

create shock, fire,

or

other

hazards.

4.

If

any repair has been made

to

the chassis,

it

is recommended the

the

B1

setting

be checked

or adjusted (See ADJUSTMENT

OF

B1

VOLTAGE).

5. The high voltage applied

to

the picture tube must conform

with

that

specified in this service manual.

Excessive high voltage can cause an increase in X-Ray emission, arcing and possible

component

damage, therefore operation under excessive high voltage conditions should

be

kept

to

a minimum,

or should

be

prevented.

If

severe arcing occurs, remove

the

AC

power

immediately and deter-

mine

the

cause by visual inspection (incorrect installation, cracked or melted high voltage harness,

poor soldering, etc.).

To

maintain

the

proper

minimum

level

of

soft

X-Ray emission,

components

in

the

high voltage

circuitry

including

the

picture

tube,

must

be

the

exact

replacements

or

alter-

natives approved

by

the

manufacturer

of

the

complete product.

6. Do

not

check high voltage by

drawing

an arc. Use a high voltage meter

or

a high voltage probe

with a VTVM.

Discharge

the

picture

tube

before

attempting

meter connection

by

connecting a

clip lead

to

the ground frame and connecting the other end

of

the lead through a 1

OkO

2W

resistor

to

the

anode

button.

7. When service is required, observe

the

original lead dress. Extra precaution should be given

to

assure

correct

lead dress in

the

high voltage

circuit

area. Where a

short

circuit

has occurred,

those components

that

indicate evidence

of

overheating should be replaced.

Always

use the

manufacturer's

replacement components.

2

SAFETY

PRECAUTIONS

(Continued)

8.

ISOLATION CHECK (SAFETY

FOR

ELECTRICAL SHOCK HAZARD)

After

re-assembling

the

product,

always

perfrom

an

isolation check on

the

exposed metal parts

of

the cabinet, screwheads, cable jacks, controls shafts, etc.,

to

be

sure

the

product

is safe

to

operate

without

danger

of

electrical shock.

(A)

DIELECTRIC STRENGTH TEST

The isolation between

the

AC primary

circuit

and all metal parts exposed

to

the

user, par-

ticularly any exposed metal part having a return path

to

the chassis should withstand a voltage

of

1,

100V

AC (r.m.s.)

for

a period

of

one second.

This method

of

test

requires

test

equipment

not

generally found in

the

service trade. *

(8)

LEAKAGE CURRENT CHECK

*

Plug

the

AC

line cord

directly

into

the

AC

outlet

(do

not

use a line isolation transformer dur-

ing

this

check). Using a

"Leakage

Current

Tester",

measure

the

leakage current

from

each

exposed metal part

of

the

cabinet, particularly any exposed metal part having a return path

to

the

chassis,

to a known

good earth ground (water pipe, etc.).

Any

leakage current

must

not

exceed

0.5mA.

ALTERNATE CHECK METHOD

Plug the AC line cord directly into

the

AC

output

(do

not

use a line isolation

transformer

during this check). Use

an

AC

voltmeter

having

1,000

ohms per

volt

or more

sensitivity

in

the

following

manner. Connect a

15000

10W

resistor paralleled by a 0.15JLF AC-type

capacitor between

an

exposed metal part and a

known

good earth ground (water pipe, etc.).

Measure

the

AC

voltage across the resistor

with

the

AC

voltmeter.

Move

the

resistor connection

to

each exposed metal part, particularly any exposed metal

part having a return path

to

the chassis, and measure

the

AC voltage across

the

resistor.

Now,

reverse the plug in the AC outlet and repeat each measurement.

Any

voltage measured

must

not

exceed

0.35V

AC (r.m.s). This corresponds

to

O.5mA AC (r.m.s.).

CAUTION:

When

troubleshooting,

with

power

applied, use an isolation

transformer

and

confirm

that

the

CRT

earth

wire

is

connected

to

the

CRT

socket

board

and

the

chassis.

3

ADJUSTMENTS

- PURITY, CONVERGENCE

AND

WHITE

BALANCE

PICTURE

TUBE

The picture tube is a precision in-line gun type. For this
picture tube, dynamic convergence is carried out by a preci­sion deflection yoke which eliminates the use

of

a con­vergence yoke and a convergence circuit. The adjustment
of

the picture tube

is

therefore made easier

as

only the ad-

justment

of

static convergence by using a magnet is
enough. The deflection yoke and purity/convergency
magnets assembly

has

been

set at the factory and requires

no field adjustments.
However, should the assembly

be

accidentally jarred or

tampered vyith, some or all adjustment may

be

necessary.

COLOR

PURITY

& VERTICAL CENTER

Loosen yoke retaining clamp

(Fig.

2-1). With a sharp knife,

cut

between the picture tube and the wedge. Remove

wedges completely and clean

off

dried adhesive from the

picture tube. PAINT is used

to

lock the tabs

of

the purity/

convergence magnet assembly in place

(Fig.

2-1). The paint

must

be

removed

with

the end

of

a screwdriver before any

adjustments

are

attempted.

1. Inject a Video Signal (RASTER)

to

the Video input

terminal.

2. Let the purity tabs come

in

line horizontally

as

is

shown

in Fig. 2-3. A long tab should

be

in the same direction

as

the other short tab.

3. Move the yoke slowly backward.

4. Tum the green cut-off control

to

maximum

and

the

red

and blue cut-off controls

to

minimum. Then adjust the

screen control

so

that the green band can

be

seen

best.

(Fig. 2-4)

5 . Rotate the

two

tabs

in

the opposite direction with them

kept at

an

angle. Move them in either direction

so

that

the green band is centered on the picture tube.

6 . Check the vertical center position by displaying a

horizontal line.

If

incorrect, bring it

to

the center by

rotating the

two

tabs, kept at

an

angle, together in

either direction. (Fig. 2-5, 2-6)

7. Repeat steps 5 and 6 alternately until the green band
and the vertical centre are

in

line.

a.

Move the yoke slowly towards the bell

of

the tube so

that

the whole surface of the picture tube is filled

with

a pure green raster.

9. Turning the red

cut-off

control

to

maximum and the

green cut-off control

to

minimum, check for pure

red

raster.

10. Turning the blue

cut-off

control

to

maximum and the

green cut-off control

to

minimum, check

for

pure blue

raster.

11.

Secure yoke retaining clamp (do

not

install wedges at

this time).

YOKE
LOCKING

RING

PURITY
MAGNETS (mark

"P")

Fig. 2-1

(REAR

VIEW)

LONG

AND

SHORT

PROTRUSIONS

Let

the

protrusions come in line

Fig.

2-3

(FRONT VIEW)

_--c..-;?""7f'7':7"T-..L

GREEN

BAND

CENTRE

Bring the green band

to

the

centre.

Fig.

2-4

(FRONT VIEW)

HORIZONTAL LINE

,~.....

f

'

..

/:.....

VERTICAL

CENTRE

(identified

with

a

'---

white

notch)

Bring

the

horizontal line

nearest

to

the

white

notches

shown

in

the

dotted

circles.

, ,

, I

."

Fig.

2-5

(TOP VIEW)

RDG

.

l~J,--

___

--,

Select the

cut-off

service

switch

from N to

S. and a

horizontal line

will

appear.

Fig.

2-6

4

STATIC CONVERGENCE & DYNAMIC CONVERGENCE

Static convergence

is

achieved by four magnets located

on the neck, nearest the

base

of the picture tube. The front

pair

of

magnetic rings (closest

to

the purity tabs)

are

ad-

justed

to

converge the red and blue crosshatch lines.

The rear pair of convergence rings (closest

to

the base

of

the picture tube)

are

adjusted

to

converge the magenta

(Red/Blue) and green crosshatch lines.
Dynamic convergence

is

achieved

by

tilting the deflection

yoke, Up-Down and Left-Right.

1. Inject Video Signal (CROSSHATCH)

to

the Video in-

put terminal and adjust

BRIGHTNESS

and CONTRAST

control for distinct pattern.

2. Adjust the convergence around the edges

of

the pic­ture tube tilting the yoke, up-down and left-right.
Temporarily install one wedge

at

the top

of

the yoke.

(Fig.

2-9, 2-10, 2-11)

3. Rotate the front pair

of

tabs

as

a unit

to

minimize the

separation

of

the red and blue lines around the center

of

the screen. To adjust the convergence

of

red

and

blue, vary the angle between the tabs.

4.

Rotate the rear pair

of

tabs

as

a unit

to

minimize the

separation

of

the magenta and green lines. (Fig. 2-8)

5. Adjust the spacing

of

the rear tabs

to

converge the

magenta and green lines.

6. Apply paint

to

fix 6 magnets.

7. Remove the wedge installed temporarily

on

the yoke.

8. Tilting the angle

of

the yoke up,

down

and sideways,

adjust the yoke so

as

to

obtain the circumference

convergence. (Fig. 2-10, 2-11)

9. Insert three wedges

to

the positions

as

shown

in

Fig.

2-12

to

obtain the best circumference convergence.

10. Secure wedges

in

position

with

the adhesive backing
provided or use a non-conductive silicon/rubber
compound.

11. White balance adjustment (Black & White tracking) can
now

be

performed.

WHITE BALANCE ADJUSTMENT

(Black and White Tracking)

1. Inject a Video Signal

(RASTER)

to

the Video input

terminal.

2. Set the

red

and green drive controls for their

mechanical center.

3. Turn the red, green and blue

cut

off

controls and the

screen control fully counterclockwise.

4.

Change the service

switch

as

shown

in Fig. 2-6,

to

the

"S"

position.

5. Turn screen control slowly clockwise until a very faint
horizontal line appears.

6. Turn the cut

off

control

of

the color which has ap­peared first, clockwise by about 10° and then adjust
the screen control again

so

that

the color may shine

faintly.

7. Turn the other color cut

off

controls slowly clockwise

until a reasonable white line appears.

8. Return the service switch

to

normal

(N)

position. (Fig.

2-6)

9. Adjust the red and green drive controls for best

white

highlights.

(FRONT VIEW)

(FRONT VIEW)

RED

AROUND

l)

BLUE

r

GREEN

\

AROUND~

CENTRE

~

MAGENTA

CENTRE

.'

. ' ,

Fig.

2-7

Fig.

2-8

(REAR VIEW)

(l)WEDGE

DEF.

YOKE

Fig.

2-9

(FRONT VIEW)

BLUE

r

;\1.<

BLUE

-_."

I

""

RED

GREEN-~,,~'----~I~--~:~_'~-GREEN

RED -,."

,;'--

_BLUE

>+~,

BLUE

GREEN

RED

Tilting

the

yoke

upward

will

move

the lines

as

shown

with

the

arrows.

Fig.

2-10

(FRONT VIEW)

Tilting

the yoke

upward

will

move

the

lines

as

shown

with

the

arrows.

Fig. 2-11

(REAR VIEW)

ANODE CAP

Fig.

2·12

5

NOTE:

1702

locations in (

).

81 VOLTAGE - Inject a video signal
1701

(110V)

Regulate VR, R109, for

B1

adjustment so

that

Dc voltage between TP-91 and earth is

110

volts.

1702

(125V.)

Confirm

that

the voltage at TP-94 and IC901 pin 4 is

125

volts.

NOTE:

Meter should

be

periodically calibrated at

20K

ohms/volt.

FOCUS

Adjust

the FOCUS control for best overall definition and picture detail at normal brightness and contrast.

VERTICAL POSITION
Adjust

the V. center

VR

R428 (R429)

to

the optimum vertical picture position.

VERTICAL HEIGHT

AND

LINEARITY

1. Display a pattern which allows easy confirmation

of

symmetry

(such

as

a circle or crosshatch).

2. Reduce the vertical size

with

the

V.

HEIGHT VR.

3. Adjust the vertical linearity

with

the V. LIN. VR.

4. Readjust the vertical height, so

that

the picture extends

to

normal size.

HORIZONTAL WIDTH
Adjust

H.

WIDTH control coil

L503

(L522) by turning it

with

a hexagonal adjusting bar only

if

RIGHT

and

LEFT

sides

of

picture

can't

be

seen.

HORIZONTAL OSCILLATOR

1. Set the

H.

FREQ.

VR

to

the mechanical center position.

2. Connect a jumper clip between TP-33A and TP-33B.

3. While rotating the

H.

FREQ.

VR, R504, keep the picture stationary or

slowly

moving.

4. Remove the jumper wire.

5. Make sure

that

the set maintains horizontal sync, when signals are switched.

6

SUB

TINT AND SUB

COLOR

1. Display a picture and set the

tint

and color VRs on the control panel

to

the central click position.

2. Adjust the sub

tint

VR, R305 and sub color VR, R303

for

the optimum display.

SUB

CONTRAST AND

SUB

BRIGHT

1 . Display a picture and set the contrast and bright VRs on the control panel

to

the center click positions.

2. Adjust

the

sub contrast VR, R209 and sub bright VR, R22 (R863)

for

optimum display.

COLOR SYNC

1 . Display a color video signal.

2. Connect jumper clips between TP-40 and earth

(TP-E)

and between TP-51 and IC301 pin 15

(TP-51

B).

3. Use a non-metallic screwdriver

to

turn trimmer capacitor

C308.

4. Adjust so

that

the rolling color stripes become

thick

and the rolling slows or stops.

5. Remove jumper clips.

6. Confirm

that

color sync is

not

disrupted when signals are switched.

3.58

MHz TRAP

1 . Receive a Video Signal into the Video input terminal.

2. Connect oscilloscope probe

to

DL201 (Delay Line)

output

side.

3. Turn the core

of

T201 so

that

that

3.58MHz

signal is minimized.

MINIMUM

7

e

AUDIO

Y

(CHROMI-

NANCE)

C

(LUMI-

NANCE)

AUDIO VIDEO

L~

~J

r;:l

F

R

F

6

I

i-+81

0

,....

I

I

R

-0

-

..............

1

;J

SIGNAL

SELECT

S

R

0)

0

'-'

F

<"-~

"-

"

I

e

1701/1702

BLOCK

DIAGRAM

!AUDIO

AMP!

It

r-::UTPUT

&.

DRIVE

I I

3.58

f-"o

3.58

TRAP

SW

TRAP

~

DELAY

VIDEO

BUFFER

VIDEO

AMP.

&.

SYNC.

SEPARATOR

I

BUFFER

l

BP

AMP.

KILLER

I

CONTROL

I

iii

i I i

I I I I I I

I

VIDEO

I Y

AMP.

I

1

SUPER

SCREEN I

CONTROL

COLOR

e

fll.

r---c;

><

~

irE

r---

I-

C

::E

F:

FRONT

R:

REAR

BUFFER

JSANDPASS}-

FILTER

COLOR DE

MOD.

DIFFERENCE

1

'---

&.

ETC.

(X)

POWER

TRANSF:

LINE

FILTER

&.

FUSE

ACIN

I

.1

VOLTAGE

J

RECT. CONTROL

-B1

I i

VERTICAL

V. OSC

&.

V.

AMP.

I--

OUTPUT

~

------------

,.....

H.

AT

C

&.

H.

OSC

I

HORIZONTAL

HORIZONTAL

t--

OUTPUT

DRIVE

I

X-RAY

prOTECTOR

B1

roo--

V

I

--

---

H

'----

HIGH

VOLTAGE

I

RECT.

CRT

Rial

150

r---

)(

3

~2

----,

Buffer

-ope.n

;

no

color

:

eo

0""

is

.©~short}

I .

-@-®shart.

fuint

C202

-----,

For sync.

"",pli

fie

....

em

Itt~r

.5

)"nOoth

i~

-ope

It

~

fa.

u It)' sync.

- R2.oI,R202,C2o3

Sync. sera

n~tor

•

!?ZOZ.

cplU\

:

fa~lt)'

I

Dc,Rh~:~

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C2 \ I

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~hostin~

-R204

0f~t\ ~ Sc~en

bq.col"neS~

~~9.

ht

I

VIDEO CIRCUIT

-$hort

: f""dtr

sr(\~·

~ln'I\"tc!'Y

t;~

-cansiaht

.

In"

\

Ope"

J

,C203

ope".

Sr

t1

c..

.c.2.o3c;hort

I

-J.

.&

It

'open:I"lO

picfClre

-snun.:

Ill"

r

synchTohitat;on

-ShoTt.

:1"10

Y/1s1e

r

L204

~-------~

F're<t."Eh?

chl1

yo.

¢teris

tic.

13.6V

X352

r--

R

-2-O-

1

---';"'--~-lL

201

ISOK

820

2SC16S5

,2SCISI5(Y,GR)

6V

BUFFER

R202

t.

aK

R353

82

XIOI

2SCI685,2SCI959(Y)

CIOI

RI02

VIDEO

AMP

470/6.3

150

RI03

390

RI04

2. 2K

- -

~/=

CI02

T

~331

6.3

-

16VP-p

(VI

14V

C351

'---1.4-V-P-'p--'

101

16

~U'

II

~

~

X351

I

C251

:=47/16

~

r--+--~--+---~

/

,IC20J

/

R207

L

203

/

HAI1401

6.aK

270

VI DEO a

SYNC

/

SEPAl

/

R250

R251

10K

10K

OV

'-

__

(e)

.....

_T_1¥12_4

.....

2'-""SCL.C.:.....16-""..S'-'-5_.

2_S_C......;I,--

8I5_{

Y--,'

IGR)

.l. / BUFFER / .

----

X\O\

--~-~

Vic!eo

amp.

·ope".

}

-®~

short

:"0

pic.tl4re

-@-@

short

-@

-e

S~ort:

Screen

is

dl1Tk

X351

---':""'"

Buffer

~;~:

shoTt

}:no

c.olor

·~-~short

-@~

shert

: color

is

faint

C20\

----'---,

f\.c.

co~pl;F\~

-open

:

110

pidl.(re

·short :

tal.\\

\ r

synchroniZPot;on

r-----

C 205"

-'---,

Differehti~1

(aperture

compensation:

'mllinly

preshooti

j'~)

·open

:

imo.~t

is

shu

rp

·short: screen ;,5

do.:rk.

Differentca.l

(aperture

CClnP'!n~tion:

lno.inly

overshcotin~)

.

~o'7

ope"

}

.<;2O'Topen

:

jma~e

is

-

"short

soft

/

T

C211

270

-

I

/'i:5_~

'2C]~

DL201

,.....A.,f\IIr+--tlI--+-J

I

R2r4

R203

2.

K

IBK

C

20

4

""T""...L

\/

3.3/50BP

-:::-

/,

COy~<:.t;ol"l.

-open. :

imo.,e

is

soft

R206

---,

S.,.Al\kir1

pu.lse

i"

"";;.

lesistQnce

-

open

:dark

piduR

CIRCUIT

NOTES

,

Although specifically written

on

the

170

1 monitor, most circuit theorlea

apply to the

1702

alao. Refer

to

the

1702

schematic for differences

In

c0m-

ponent values and IdentlflQatlon.

R206/

I

r-

__ ~ __ ~ ____

~3A·3~K

____

~~

R210

!

330

270

__

--

R209

SUS

'"I

I K

CONTRA~

I

X250

-

,.-

___ 2SCISI5 (Y,GR)

SWITCHER

T201

3.S8MH

Z

TRf

o?

6Vp.p

rvL

(HI

X202

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

Vide.o

a,mo

.

I

-

R2.IO

Men

l

·R

2.1'

O~i'\

j : l"(Q ra.ster

"R2t2

c~"-

}

rIO

pldu.~

·x20Z

~:HI>skt:

:s...-reen

is

Ilbnortnally

~-0ShCft

hri'3

ht

I»"Id

flybaCk

@-®Short

t

line

Cll'pears_

•

X202

ODefl

: no YQS ter

I

R2.0~

.R2.0'/,

R223,c2/o

----,

Emitter

';)(as

and

freb'.H?hC;

.

chlll""cteristic

con-ec.

tiot\.

•

Rloe

OP"'h}

.

'C210

shOTt

:no

p,ctl\~

HA/l401

TROUBLE" SYMPTOM

DF

PRESIJME

...

X2~D

-----..,

Switche.r

·©-@short:color

error

'@

-@

short:

sc

reel'l

b~cctneS

briqht

and

vertical stripes

T201

-----.,

3.

SRMHt

tro..p

co\1

-Optm.

no

pic

tl4Te

-shoTt:

3.!;RMliz trap

dot

interference

-110

Tas.ter. no

Sound

.ho picture

-

sc.reen

is

too

Fn'i~h

t

•

SCree.n

is

dark

'multI

sync.

. raster is

brl~ht

Clhd

flyback line

ar~Qy".s

•

\ma~e

~ua.\;ty

is

un

sa.

tis

-Factory

I

9

"R65D,C651

1hp'4

to

'n!s~s

tClttce

unci

condehser

C6~2

,.--

"R(,!)!

,R6S2

Bias

l'eSisto.hCe.

·open: sound levei

becc

lY\es

h

i'jh

F

R6IS

-

~

n!Si~l1lnce

~

C6~D

Noise ab-;orb

·shot"t

:hO

SOUI\Q

I

-

I

.----

R607,

C60q

----,

N~t;ve

teed ha.ck 'resistClhce

(.612.

DC c.u.t cOhde.I'ISIt.'f"

.

open:

sound

level

becomes

hi~h

Boc~;,

conde.nser

~6DS',c608

Coupli~

TeSls~n~

and cOhdenser'

'F-bOS"

O~}

·c.oo&

open

:no

sound.

•

II

shari

.c?~n

:

no

souhd

ColO

---r

Couriil\l

cohd~sel'"

'opel"' :

no

')ound

T602 --......

Audio

ou~~-t

tT"(lhsf.

·open:

no

sound

"Rbi

1

------,

BillS

Y~stl1l\ce

·o~:

1"\0

Sl!l.Incl

1)601

---,

L.Ft

diode

·open: sound

!eve

I

becomes

low

R607

ISOK

\

C609

.015

200V

MY

-

C60S

.OI5MY

\C610

..--;---;-""Arr--;

i--+---+-----"W'r-i

. 4

7150

8 P

R617

470K

R615

47K..l.-

~606

.018MY

R603

~

68

~

~R61a

1"

iaOK

R6J2

~

2.2K

RG04

IK

\

IC601

HAIII07l

AUDIO

"R6D2,

R604

R608

220K

R609

6.8K

(V

X601-

R610

........

560

L7

~

"='"

-,

GC:-

4000A

--1

r

(M.\8 FR6011

(J

(00

I

112FRI

I

I

t +

l C613 .

14.711601

I

or

R61'T.

Rbl8

---,

Outfl4t

voH-C\~e

di"idih~

rec;istc~hce

.J

101l6~

fa

81 IIOV

,...---

c6ob~-

....

R603,C60S"

Filter

"Dc.

'Input

condense.r

CbI4.C6IS

-------"1

Noise

absorb

To,,~

~uQ.lj

ty

c.orrection

. short:

Y\.O

SCUtlQ

'R603

cpen

:no

sound

·R{,o2

open:sound

level

becomes

hi~.

VR

does

hot function.

'RbD4

(lpen:

sound

Ie.

vel

becomes

10

w.

. (;614

short:

soul'\d

level becomes

hiljh.

VR

does

hot

fundio/\.

.c

bll,;

~rt:

sound

ic.;

not

Cl",dible

unless

VR

is

"turned

at

least

ho.lf

way.

AUDIO CIRCUIT

XboZ

.X603

-------.,

Audio

out

·open:sound

level

becomes

low

and

lacks

bass.

R613.

R614

---~

BOola

t\c~

fesistllnc.e

• open: sound

leve.l

beComes

low

and

lacks

bass

;<601----.

AudIO

c!ri

ve

·open

~:

1\0 $Qohd

·short

1

FR601.

cbi3

---,

FilteY'

.

FF-(,o\

open:

noSouM

CIRCUIT NOTES

Although specifically written on the
1701

monitor, most circuit theories

apply to the

1702

also. Refer to the

1702

schematic for differences

in

com-

ponent values and identification.

10

•

1'10

piduye

T30i

---,

BP

take~off

transf.

,----

c302

Br-~~

conQenser

.open:

colD\"

beccmcs

$rk

'short;

no

color

R!oi---.,

Dumpi~

~is~nce

"open

:c%Y

error

4Vp-p

C303

N:.c

smoomlnj

•

open : no

~clor

R3,-3

Emmire~

~

...

-tGn~1e

-

C3

0

4-

Cou~in3

Cl)ndens~r

.open:

hD

coloy

"sheet:

no

picture.

c30S

--...,

K i

\l~

smocil\,'i

.

.:yw

"\:

ltO

~Ior

's~rt\

C304i:C305

180

-.45/50

R328

1M

R302.R303

Co\Oy

c:orrec.tloh

(bleeder

feS'StllllC~)

color

i~

'R3Dl

open:

faint

'R303

nDf!Tl:

color

is

·r _ ..

dink

R304,

R3DS,

R322

tl\'\t

c.orrectlon.

(bleeck.r

..-n\S~)

·R304

ore"':

Yec:\

ro.steY'

be.comes

lnDihel11'o...

'R:30!)

'f"'l

Hed

bf.CDtneS

"ftl,,,t.

~

beCCl'les

bi

...

e \:)ecomes vic,e.,-.

·R311. ~ :

titlt

VR

doeS

!\Of:

fu

nc-U

on

R.321

.-

____

AAr...rIK

___

_

+

10.7V C

316

z:::

10116

I

~

/

I

R316

22K

·only

tnDl1Ocln·omAtic.

·no ccioY,

edDY

-fad~

away

·no

monochroma.tic..

+.d-

IC301

HAII247

B.P

AMP,

ACC,KI

TINT,

APC,

VCO

a COLOR

OEM

I

.'

· fnultr

tint

"c.cicr

no;SE!

• cclor el'"rcr

.

faulty

color

sync.

. czlcr

beat

·dc.

..•

.----c306

Diff4e~n"ti4TeS,'5rnc.

si~

",,\,

a,"'cl

clela.ys

fho.o;e

of- pllise.

'OI'en : r-o"coloY

. short :

1'0

pIC

tttYl!.

dark

yaster

TP~5°1

I

~

0301:!:

I

S2473H

~5~6

C306

180

T

~

~

0302_.

ER,

1 S 2

47

3 H

,-c~r-.-:.::I

5::.:.1.:.55:,:5::.,

0303-0308

W06-A,W06-8,151555

R310

L351

330

~~-+----------~~.-~

or 1512473

22

0307 I R311

330

I

~----------~------.-~~-+-~

0306

I I R312 3301

G~53--~~~I~~~I--r-~I-~

R314

22

:.

~

•

J30g

2.2K

~

-:-

..!...

R322

~

10K

030'1,

R307.R30!i'-L.----.

For

phase

shOt

ft

C310,C311,C312

---,

'By"

p'l~'"

condl!nser

--

D

30

I

.---I.~-,

Foy

noise

prevention

.shon::

c:oloY'

errOl"

'C30'7

short

:5C~n

bec..::m'!s

bei'.1ht

\:I."t

ho

ccjOl"

'00'7

opt'll

}

obtain~

"R307

open

:no

color

"R301?

cpen

(ootp'lt

"IT;..

ba.se-~TCu.ncied

with

T6rect to

\U7'O\i"o."c:e

sl'y,a.I)

.

<:310

shan'

no

caree.n

Y'IsteY

.

C311

shcrt:

hO

red

ro.S

teY

·c312.

short:

no

bilAe.

ra.s!er

130 I. c 30&>,R3o'7,

c309 -

3.s8MH~

filhr

·'('3ot

o~n

,';hoT"t }

·c308

op~"

:tlO

colo

...

'R30'1

open

'C

3017

ope

...

,

sho~t

G3\3,C

314,

R3\3.

R~\4

APC

s",ooth~,,:}

'C313

Shod}

.c314

shOTt

:1\0 color

. R 3

i4-

open.

~-

L351,L31>2.

L3S3

t\

;,h

t"re:tu'!n"ff:

It

~Y"

·

L?S

\

opQ.n:

ydlcw

fictu.re

· L

~52

~

:cpM;c.rictLlI't.

· L 3

S"3

,,~"

:

m<l:1',enta

ftC.tun~

COLOR

DEM. CIRCUIT

"f..301.R315;1~3

1.6.

R3f'7

R3i'iLR321,C316

Su.~r-scene

ccnh-ol

'R~15

open.

"R

316

open

Got\t~st

'R31'T

oru'

becomes

.R32\

open weo.k

·(.31b

short

·xaot

open

CIRCUIT NOTES

Although speciflcally written on the
170

1 monitor, most circuit theories

apply

to

the

1702

also. Refer to the

1702

schematic

for

differences

In

com-

ponent values and Identification.

D302.---...,

Be"'" I:",iter

diode

. short :

br;~h+et1.

R310,R3i \,R3i2

----,

Ie

pl"t'tection reSistor

'R310

"pet:

yellow

i';ct

......

e

'R311

·R312.

cpen: cyanic p;cture

open. :

1Tla.'Jhent~

t

1

pIC

ure

D303

.......

D308

Roted,on.

of

Ie

frt,.,,,

CRT

SFrki"~

·E>303

short:

bllA4e

picture

"i)

304

short: · ....

ed

pIC

Tt.U'e

,-£)30 S

short:

~reet'\

fic

rure

1 1