EMERSON TC1973D Service Manual

COLOR TELEVISION RECEIVER

TC1973D

Irr!

UHF
CATV

0 . . . .

1

SPECIFICATIONS

1

All the specifications and features are subject to change without notice.

DISASSEMBLY INSTRUCTIONS

1. REMOVAL OF ANODE CAP

Read the following NOTED items before starling work.

After turning the power off there might still be a potential
voltage that is very dangerous. When removing the
Anode Cap, make sure to discharge the Anode Cap’s
potential voltage.
Do not use pliers to loosen or tighten the Anode Cap

’

terminal, this may cause the spring to be damaged.

REMOVAL

1.

Follow the steps as follows to discharge the Anode Cap.

(Refer to Fig. l-l.)

Connect one end of an Alligator Clip to the metal part of a

flat-blade
While holding the plastic part of the insulated Screwdriver,
touch the support of the Anode with the tip of the
Screwdriver.
A cracking noise will be heard as the voltage is discharged.

screwdriver and the other end to ground.

GND

on the CRT

3. After one side is removed. pull in the opposite direction to
remove the other.

NOTE

Take care not to damage the Rubber Cap.

INSTALLATlON

1. Clean the spot where the cap was located with a small

amount of alcohol. (Refer to Fig. l-3.)

GND on the CRT

2. Flip up the sides of the Rubber Cap in the direction
arrow and remove one side of the support
(Refer to Fig. l-2.)

Rubber Cap

Fig. 1-l

of

the

NOTE

Confirm that there is no dirt. dust, etc. at the spot where
the cap was located.

2. Arrange the wire of the Anode Cap and make sure the
wire is not twisted.

3. Turn over the Rubber Cap. (Refer to Fig. l-4.)

Fig. 1-4

CRT

V

Support

Fig.

1-2

4

DISASSEMBLY INSTRUCTIONS

4,

Insert one end of the Anode Support into the anode button.

then the other as shown in Fig. I-5.

Fig.

5. Confirm that the Support is securely connected.

6. Put on the Rubber Cap without moving any parts.

2. REMOVAL OF DEFLECTION YOKE
(Refer to

I.

Loosen the screw

2. Remove the Convergence . Purity Magnet in the

direction of arrow (A).

3. Loosen the screw

4. Remove the 3 Wedges.

5. Remove the Dellection Yoke in the direction of
arrow

INSTALLATION

tnstall new Deflection Yoke in reverse steps of REMOVAL.

NOTE

After adjusting the purity and the convergence. fix the
screw 0 and lock the wedges.

Fig. 2-1)

0.

0.

(8).

l-

Wedge

Fig.

2-.

5

ELECTRICAL ADJUSTMENTS

1. BEFORE MAKING ELECTRICAL
ADJUSTMENTS

Read and perform these adjustments when repairing the
circuits or replacing electrical parts or

CAUTION

Use an isolation transformer when performing any

sarvce

on this chassis.

Before removing the anode cap, discharge electricity
because it contains high voltage.

When removing a PCB or related component, after
unfastening or changing a wire, be sure to put the wire
back in its original position.

Inferior

sillcon

grease can damage
When replacing
silicon grease

Remove all old silicon before applying new silicon.

1-l: Prepare the following measurement tools far

electrical adjustments.

1.

Sweepmarker Generator

2. Oscilloscope

3. Digital Voltmeter

4. Color Bar Generator

IC’s

and transistors. use only specified

(YG6260M).

PC6

assemblies.

IC’s

and transistors.

L

CUTOFF

1.

VSIZE

2.

BRI.

AUTO

3.
X-RAY

4.
CONT

5.
END

8.

1.

AUTO

2. vco

3. AFT

4. AGC

5. COL

6. TINT

7.

BRI

8. END

Fig.

2-Z

f

,

.

2. BASIC ADJUSTMENTS

On-Screen Display Adjustment

the of a straightened paper clip into the hole

on remote control marked with an arrow as shown

Fig. 2-f.

The adjustment mode display will appear as shown

Fig.2-2 andFig.2.3.

NOTE

Use the

options shown in Fig. 2-2 and Fig. 2-3.

Press the 8 key to end the adjustments.

1 8

keys on the remote control to select the

Fig. 2-l

2-1: VCO AND AFT
NOTE

Connect input and output terminals of the
sweepmarker generator to the circuit as shown

in Fig.

2-4-a,

SWEEPMAKER
GENERATOROUTPUT

-

SWEEPMAKER

GENERATOR INPUT 47Kohm

1.

Connect output terminal of

TP201.

2. Connect input terminal of the sweepmarker generator to
TP204.

3. Connect a

(TP210). 12V
wavelorm 01 the oscilloscope readable

10K

ohm variable resistor to IF AGC terminal

line and ground. lhen adjust to make the

it.

0.22

rF

lN60 4.5 pF

Ihe

sweepmarker generator to

Fig. 2-3

GND

Fig. 2-4-z

3

ELECTRICAL ADJUSTMENTS

10

Kohm

AGC TP210

4. Activate the adjustment mode display (Fig.
press the 2 key.

5. Adjust VOL. UP/DOWN key on the remote control until
the waveform maker
Fig. 2-4-b.

(45.75MHz)

45.75 MHz

becomes as shown in

2-3)

and

In case of strong electric field.
(Radio frequency interference can

streaks to appear.)

1. Activate the adjustment mcde display and press

2.

Press the VOL. UP/DOWN key 0” the remote

diagonal streaks are at minimum.

3. If there is still a problem after pressing the VOL. UP/DOWN
key on the remote control. install an attenuator to the
terminals. then repeat step

4. Confirm that noise does not appear.

5. Change the channel. confirm that the other channels are

normal.

2-2-C: TINT

1.

Receive the color bar pattern.

2. Connect the oscilloscope to TP023.

3. Activate the adjustment
the 6 key.

4. Press the VOL. UP/DOWN key on the remote control
the waveform becomes as shown in Fig.

mode

cause

diagonal

rhe

control untit

1.

display (Fig. 2-3) and press

2-5.

4

key.

antenr,

until

x

Fig. 2-4-t

6.

Disconnect output terminal 01 the sweepmarker generator

from

TP201,

then connect it to TP al the tuner pack.

7.

Disconnect the
resistors.

6.

Disconnect input and output terminals of the
sweepmarker generator.

9.

Connect the AFT adjustment oscillator

to TP of the tuner pack.
1 O.Connect the digital voltmeter to TP206.
1

l.Activate

the 3 key.

12.Adjust

2-2: BRIGHT, AGC, TINT AND COLOR
2-2-A: BRIGHT

1.

Receive the monochrome pattern.

2. Activate the adiustment mode displav

3. Press the VOL. UP/DOWN key on the remote control

2-2-B: AGC
NOTE

In case of weak electric field.

1. Tune to a noisy channel.

2. Activate the adjustment mode display and press

3. Press the VOL. UP/DOWN key on the remote control

4.

VOL. UP/DOWN key on the remote control to find
the point where the voltage of
and adjust to

press the 7
until the boundary between 0% and 10% white starts

to become visible.

Adjust after performing adjustments in section 2-1.

the 4 key.
until noise is at minimum.

Change the channel. confirm that the other channels
are normal.

10K

ohm and the

the adjustment

4.5VDC

ke;.

at that point.

2.7K

ohm variable

(45.75MHz)

mode

display (Fig. 2-3) and press

TP206

changes dramatically,

(Fig. 2-3)

,.

”

and

1

_

2-2-D: COLOR

1.

Receive the color bar pattern.

2. Connect the oscilloscope to TP022

3. Activate the adjustment mode (Fig. 2-3) display and press
the 5 key.

4. Adjust the VOLTS RANGE VARIABLE knob of the
oscilloscope until the range between white 0% and 1 CO%
is set to 5 scales on the screen of the oscilloscope.

5. Press the VOL. UP/DOWN key an the remote control
the red color level is adjusted to
white level. (Refer to Fig. 2-6)

4.75scalesf95%1

I

Fig.

2i

untii

for

:he

I

h-

J

k

b+4

LL

I

I

95%

I-_-_-

--OX

--

100%

7

ELECTRICAL ADJUSTMENTS

2-3: CUT OFF

1.

Receive the color bar pattern.

2. Using the remote control. set brightness and contrast to

mm~mum

3. Connect the oscilloscope to TP024.

4. Adjust the
(Refer to Fig. 2-7)

position.

screen

volume until voltage is

---­.

.

.

.

15OVDC.

.-

--

*

.

I

DC1

50V

GND-

2-4: FOCUS

1.

Receive

2. Adjust the focus control until picture is distinct

the broadcasting signal.

Fig.

2-

I

7

1

2-5: VERTICAL SIZE

1.

Receive the crosshatch pattern

2. Activate the adjustment mcde display (Fig.
the 2 key.

3. Press the VOL. UP/DOWN key on the remote control until

the horizontal

2-6: VERTICAL POSITION

1. Receive the color bar pattern.

2.

Using the remote control, set brightness and contrast to
maximum position.

3. Adjust the value of R429 and R430 until horizontal line of
the color bar comes to approximate center of the CRT.

NOTE

R429 and R430 are fixed resistors. Use a variable

resistor to determine the optimal value and insert that
value resistor.

Lessen the value of R430
Lessen the value 01 R429

2-7: HORIZONTAL POSITION

1.

Receive the color bar pattern.

2. Adjust the value 01 R443 and

01

both screen edges are equal.

3. Receive the broadcasting signal, then confirm picture is
normal.

NOTE

R443 and
resistor or capacitor to determine the optimal value and
insert that value component.

Lessen the value of R443
Lessen the

overscan

C466

value 01

is equal to the vertical

are fixed components. Use a variable

C460

lrom

the color bar generator.

2-2)

and press

averscan.

Picture will
5mm UP.
Picture will move about
5mm DOWN.

C460

until the color width

Picture

will move right.

Picture Will move left.

move

about

8

ELECTRICAL ADJUSTMENTS

3-3:

I

3. PURITY AND CONVERGENCE
ADJUSTMENT

NOTE

1. Turn the unit on and let it warm up
minutes before performing the following adjustments.

2. Place the CRT surface lacing east or west to reduce the
terrestrial magnetism.

3. Turn ON the unit and demagnetize with a

3-I: STATIC CONVERGENCE (ROUGH ADJUSTMENT)

1.

Tighten the

CRT for the position. (Refer to Fig.
If the deflection yoke and magnet are in one body,

untighten

2. Receive the green raster pattern from color bar
generator.

3. Slide
side 01 the CRT.

4. Adjust center of screen to green. with red and blue on the
sides, using the pair of purity magnets.

5. Switch the color bar generator from the green raster

pattern to the crosshatch pattern.

6. Combine red and blue of the 3 color crosshatch pattern

on the center ol the screen by adjusting the pair of
4 pole magnets.

7. Combine red/blue (magenta) and green by adjusting the

pair of 6 pole magnets.

6. Adjust the crosshatch pattern to change to white

by repeating steps 6 and 7.

3-2:

PURITY

NOTE

Adjust after performing adjustments in section 3-1.

1.

Receive the green raster pattern from color bar

generatar.

2. Adjust the pair of purity magnets to center the

color on the screen.
Adjust the pair of purity magnets so the color at ends are
equally wide.

3. Move the deflection yoke backward (To neck side)
slowly. and stop it at the position when the whole
screen IS green.

4. Confirm red and blue colors.

5~

Adjust the slant of the deflection yoke while watching the

screen. then tighten the fixing screw.

xrew

for the magnet. Refer to the adjusted

the screw for the body.

the

deflection yoke until it touches the funnel

for

at least 30

Degauss

3-l)

DEFLECTION YOKE
DEFLECTION YOKE SCREW
MAGNET SCREW

Coil.

STATIC CONVERGENCE

NOTE

1. Receive the crosshatch pattern lrom color bar generator.

2. Combine red and blue of the 3 color crosshatch pattern
on the center of the screen by adjusting the pair of
4 pole magnets.

3. Combine red/blue (magenta) and green by adjusting the
pair of 6 pole magnets.

3-4:

DYNAMIC CONVERGENCE

NOTE

Adjust after performing adjustments in section 3-3.

1.

Adjust the differences around the screen by moving

the deflection yoke upward/downward and right/left.
(Refer to Fig. 3-2-a)

2. insert three wedges between the deflection yoke and
CRT funnel to
(Refer to Fig. 3-2-b)

UPWARD/DOWNWARD SLANT

\

NEDGE

lix

the deflection yoke.

Fig. 3-2-a

0

WEDGE

WEDGE POSITION

Fig. 3-2-b

RIGHT/LEFT SLANT

/

WEDGE

Fig.

PURITY MAGNETS

6 POLE MAGNETS
4 POLE MAGNETS

3-l

9