Skyworth 1418, 1422, 2122, 1498, 2522 Service Manual

SKYWORTH

®

SERVICE MANUAL

COLOUR TELEVISION PAL/SECAM BG/DK /NTSC
PLAYBACK

CHASSIS : 3N10, 4N10
MODEL : 1418, 1498, 1422, 2122,

2199, 21F1, L21, D21

CHASSIS : 5N10

MODEL:2522, 2588,25F1,2998,

2922
2929,29F1,3423, 3498,

3898,
L25, D25, L29, D29, L34,
D34

3N/ 5N10 7-2-2001

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CONTENTS

PAGE

X-Ray RADIATION PRECAUTION

2

SAFETY PRECAUTION

2

PRODUCT SAFETY NOTICE

2

CHASSIS

3

COMPLETE MACHINE GENERAL

3-5

NOTES………………………………………………………………………………………………

5-9

COLOUR PURITY AND CONVERGENCE ADJUSTMENT

10

BLOCK DIAGRAM

11

WIRE DIAGRAM

12

SCHEMATIC
SPECIFICATIONS………………………………………………………………….………………

1

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CAUTION

Before serving the chassis, read the "X-Ray Radiation Precaution", "Safety Precaution"
and "Product Safety Notice" on page 2 of this manual.

X-RAY RADIATION PRECAUTION

1. Excessive high voltage can produce potentially hazardous X-Ray Radiation. To avoid such
hazards, the high voltage must not be above the specified limit. The normal value of the high
voltage of this receiver is 24KV at zero beam current (minimum brightness) under 220V AC
power source. The high voltage must not, under any circumstances, exceed 29KV.

2. Each time a receiver requires servicing, the high voltage should be checked following the
High Voltage Check procedure in this manual. It is recommended the reading of the high
voltage be recorded as a part of the service record. It is important to use an accurate and
reliable high voltage meter.

3. The primary source of X-Ray Radiation in this TV Receiver is the picture tube. For continued
X-Ray Radiation protection, the replacement tube must be exactly the same type tube as
specified in the part list.

4. Some parts in this receiver have special safety – related characteristics for X-Ray Radiation
protection. For continued safety, parts replacement should be undertaken only after referring
to the Product Safety Notice.

SAFETY PRECAUTION

Warning: Service should not be attempted by anyone unfamiliar with necessary precaution on
this receiver. The following are the necessary precautions observed before servicing this
chassis.

1. Since the power supply circuit of this receiver is directly connected to the AC power line, an
isolation transformer should be used during any dynamic service to avoid possible shock
hazard.

2. Always discharge the picture tube anode to the CRT conductive coating before handling the
picture tube. The picture tube is highly evacuated and if broken, glass fragment will be
violently expelled. Use shatter proof goggles and keep picture tube away from the
unprotected body while handling.

3. When replacing a chassis in the cabinet, always be certain that all the protective devices are
put back in place, such as: non-metallic control knobs, insulating covers, shields, isolation
resistor-capacitor network etc.

4. When replacing parts or circuit boards, disconnect the power cord.

5. When replacing a high wattage resistor (Metal oxide film resistor) on circuit board, keep the
resistor 10mm (1/2in.) away from circuit board.

6. Connection wires must be kept away from components with high voltage or high temperature.

7. If any fuse in this TV receiver is blown, replace it with the FUSE specified in the chassis part
list.

8. The receiver is designed to operate with 220V(50/60Hz) AC mains.

PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in this chassis have special safety-related characteristics.
These characteristics are often passed unnoticed by a visual inspection and the X-Ray
Radiation protection afforded by them cannot necessarily be obtained by using replacement
components rated for high wattage, etc. Replaced parts which have these special safety
characteristics are identified in this manual and its supplements, electrical components having
such features are shaded on the schematic diagram and the part list.

Before replacing any of these components, read the part list in this manual carefully. The use of
substitute replacement parts, which do not have the same safety characteristics, as specified in
the part list may create shock, fire, and X-Ray Radiation or other hazards.

2

CHASSIS ADJUSTMENT

1. B+ voltage adjustment (For 3N and 4N chassis only)
1-1 Connect 220V AC 50Hz to CN601 and switch on power switch SW601;
1-2 Test the voltage with digital voltage meter between two terminals of C625;

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1-3 Adjust VR601 to obtain +110V+/-0.5V reading on the digital voltage meter.
Note: The 5N chassis is auto B+ voltage by SE130 or SE140 used.

2. NTSC system absorbing adjustment

2-1 Set sweep generator marker to 31.5MHz, 33.5MHz, 34.42MHz, 37MHz, 38MHz and

40.5MHz;

2-2 Apply 80dBuV sweep signal to tuner IF terminal;
2-3 Display demodulation probe connects to pre-I.F AMP input terminal, via. Q101 'b' pole;
2-4 Set Q103 'c' pole and 'e' pole short circuit, adjust L104, and make the attenuation most at

33.5MHz.

3. Memory partial initializing

3-1 Go to the function set menu (there are two ways;)

a. Press CH+(PROG+) key and CH-(PROG-) key on the control board at the same time

and switch on power switch, then go to the function set menu.

b. After TV is on, press "factory" key (See Note 1) twin then go to the function set menu.

3-2 Press 'PM' key and 'SM' key on the control board at the same time until the picture

changes slightly (jumpiness or twinkling at one blow), this means the memory having
been partial initialized. Operate repeatedly if the picture has no change.

All of the TV set must be partial memory initialized before exfactory or after change of

the Chroma IC NN5198 / NN5199 or fully memory initialized after change of the
EEPROM 24C04 (Note 4).

4. search and storage

COMPLETE MACHINE GENERAL ADJUSTMENT

1. Screen Voltage Adjustment.
1-1 Press 'screen' key (See Note 1);
1-2 Adjust the screen knob of FBT to get a horizontal faintness beam line;
1-3 Press 'screen' key again or 'stand by' key to go to the normal work status;

2. Focus Voltage Adjustment.
2-1 Receive monoscope pattern. Set picture mode standard status;
2-2 Adjust the focus knob of FBT to get the clearest picture.

3. horizontal center adjustment
3-1 Receive monoscope pattern;
3-2 Press 'factory' key (See Note 1)one time and go to system parameter adjustment
menu;
3-3 Press 'MENU' key, go to horizontal and vertical parameter adjustment menu;
3-4 Select 'H POSITION" by pressing 'PROG+' key and 'PROG-' key. Press 'VOL+' key
and 'VOL-' key to
obtain the horizontal center of the pattern at the center of CRT screen.

3

3-5 Exit system parameter adjustment menu by pressing 'factory' key twin.

4. PAL system vertical pincushion adjustment
4-1 Receive PAL system cross hatch pattern signal;
4-2 Press 'factory' key one time, go to system parameter adjustment menu;
4-3 Press 'MENU' key, go to horizontal and vertical parameter adjustment menu;
4-4 Select 'V LINE' and 'V SCURVE' by pressing 'PROG+' key and 'PROG-' key; press
'VOL+' key and 'VOL-' key and adjust corresponding parameter to obtain picture's vertical
pin cushion a good status.

5. PAL system vertical size and vertical center adjustment
5-1 Continue operation 3. Select 'V HEIGHT" and 'V POSITION', press 'VOL+' key and
'VOL-' key adjust corresponding parameter to obtain picture's vertical size and vertical
center adjustment a good status.
5-2 Exit system parameter adjustment menu by pressing 'factory' key twin.

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6. White Balance adjustment
For Factory Auto Computer adjustment
6-1 Receive white balance test signal;
6-2 Set picture "MILD" mode.
6-3 Insert the special plug into CN002, press adjustment key which belongs to white

balance adjustment equipment and go to auto white balance adjustment;
6-4 After adjustment well, remove the pug.
For Factory Auto Computer adjustment
6-5 Press 'factory' key one time and go to system parameter adjustment menu;
6-5 Press "MENU" key once then go to the White Balance adjustment menu;
6-6 Press ‘Prog +' key and 'Prog -' key to select the R, G, B cutoff and R, B Driver.
6-7 Press 'VOL+' key and 'VOL-' key to change. Or using the below direct key
6-8 Key: 0 for SUB-BRIGHT, 1 for CUTOFF-R, 2 for CUTOFF-G,

3 for CUTOFF-B, 4 for DRIVER-R, 5 for DRIVER-B

Recall for toggle the SubBright adjustment (Min. contrast, some CPU version is not

work)

7. Sub-bright adjustment
7-1 Receive PHILIPS signal;
7-2 Set picture "Mild" mode.
7-3 Press 'factory' key one time and go to system parameter adjustment menu;
7-4 Press digital key '0', select 'SUB-BRIGHT';
7-5 Press 'VOL+' key and 'VOL-' key until Grey scale signal can be secerned;
7-6 Exit system parameter adjustment menu by pressing 'factory' key twin.

8. RF AGC adjustment
8-1 Receive 60dBuV monoscope pattern;
8-2 Press 'factory' key one time and go to system parameter adjustment menu;
8-3 Press 'PROG+' key and 'PROG-' key , select ' RF AGC ';
8-4 Press 'VOL+' key and 'VOL-' key to change the value of 'RF AGC' until picture's noise

disturbing disappears just;

4

8-5 Exit system parameter adjustment menu by pressing 'factory' key twin.

9. NTSC system horizontal and vertical adjustment
Receive NTSC system cross hatch pattern. Adjustment's way is same as PAL system's.

10. warm up mode
10-1 Switch on power switch and Press 'factory' key one time; switch off power switch

and switch on power switch again, at this time there is no signal white raster and won't

switch off automatically. TV receiver can be sent to warm up line.
10-2 Before exit warm up line, press 'factory' key three times continue, at this time exit
warm up mode , there is no signal and will appear LOGO pattern.

NOTES:

1. Connect the remote IC PIN7 and PIN16 through a jiggle switch on the USER remote handset ,
this switch is defined as "screen" key; Connect the remote IC PIN8 and PIN16 through a jiggle
switch on the USER remote handset , this switch is defined as "factory" key,

2. On the product line's alignment service we must use special memorizer that has been well
written data.

3. If having no special memorizer that has been well written data when servicing out of factory,
we can use blank new EEPROM. EEPROM will be automatically totally initialized after main
power switch is on. Most parameters are free-alignment after initialized; only need adjust the
several parameters of function set parameter and system parameter adjustment menu.

4. If no blank new EEPROM or no special memorizer that has been well written data, we can use
memorizer that has been written data instead, but must be totally initialized; the operation is

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as following:

1. After TV is on, press "factory" key twin then go to the function set menu;

2. Press 'AV/TV' key and 'MENU' key on the control board at the same time until the
picture changes slightly (jumpiness or twinkling at one blow); this means the memory
having been totally initialized. Operate repeatedly if the picture has no change;

3. Switch off and exit;

4. After initialized, adjust the several parameters of function set parameter and system
parameter adjustment menu.

5. the parameters of function set parameter and system parameter adjustment menu mustn't
be adjusted;

1. system parameter adjustment menu (This is coming from the NN5198/ NN5199)
AFT
VIF VCO
H VCO
VIFDET NEG
VIFDET INT
VIFDET EXT

2. the ninth digital and the tenth digital of function set parameter
These parameters must be IC interior values. If the above parameters have been
changed, we must partially initialize the EEPROM.

5

6. two different initializing

1. fully initialize: initialize the EEPROM's most work data and preset default value.

Including: work parameter of NN5199, horizontal and vertical parameter, OPTION
parameter (via. function set parameter), picture mode parameter, volume mode
parameter and white balance parameter.

2. partially initialize: only initialize work parameter of NN5199 and the ninth digital and

the tenth digital of function set parameter(via. ISUD0,
ISUD1,ISUD3,ISUD4,ISUD5),preset as interior values.

7. If use 21” Pure Flat tube , must adjust horizontal size and pincushion distortion as following:

1. Receive monoscope pattern; Adjust VR902 until overscan ratio (scanning size)to 92%
to 96%

2. Receive cross hatch pattern signal; Adjust VR901 until the pinchusion of the CRT two
sides are most straight.

8. If use 25” or above Pure Flat tube , must adjust horizontal size and pincushion distortion as
following:

1. Receive 60dBuV PAL system monoscope pattern;

2. Press 'factory' key one time and go to system parameter adjustment menu;

3. Press 'MENU' key and select ' Position Menu ' as below
V POSITION for adjust vertical position 00 to 07
H POSITION for adjust Horizontal position 00 to 1F
V EHT for adjust vertical shape 00 to 0F
H EHT for adjust Horizontal shape 00 to 0F

4. Press 'MENU' key and select ' geometry Menu ' as below;
V-AMP for adjust vertical size 00 to 7F .
V_LINE for adjust vertical linearity 00 to 3F.
V_SC3 for adjust vertical S-correction X

3

00 to 3F.
H-AMP for adjust Horizontal size 00 to 3F.
EW-PARA for adjust Pincushion 00 to 3F.
EW-COR for adjust Pincushion corner 00 to 0F.
TRAPEZ for adjust trapezium 00 to 3F.
V_SC5 for adjust vertical S-correction X5 00 to 0F.

5. Receive 60dBuV NTSC system monoscope pattern;

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5.1 Repeat the above step 7.2 to 7.4.

6. Exit system parameter adjustment menu by pressing 'factory' key twin.

9. Option Code

1. Press 'factory' key twin and go to Option Code Menu

The first digit 8 Digit is set by Factory. The last two digit “9” and “A” is the random data from
NN5198/NN5199.
Option digit 1:

Binary Dec Function Default

000 0 SECAM L OFF, SECAM OFF, NTSC OFF
001 1 SECAM L OFF, SECAM OFF, NTSC ON

Default 7

6

010 2 SECAM L OFF, SECAM ON, NTSC OFF
011 3 SECAM L OFF, SECAM ON, NTSC ON
100 4 SECAM L ON, SECAM OFF, NTSC OFF
101 5 SECAM L ON, SECAM OFF, NTSC ON
110 6 SECAM L ON, SECAM ON, NTSC OFF

111 7 SECAM L ON, SECAM ON, NTSC ON

Option digit 2:

Binary Dec Function Default

000 0 RGB Beam limit ON, Woofer OFF, Sharp increase at 3MHz
001 1 RGB Beam limit ON, Woofer OFF, Sharp increase at 4MHz
010 2 RGB Beam limit ON, Woofer ON, Sharp increase at 3MHz
011 3 RGB Beam limit ON, Woofer ON, Sharp increase at 4MHz
100 4 RGB Beam limit OFF, Woofer OFF, Sharp increase at 3MHz
101 5 RGB Beam limit OFF, Woofer OFF, Sharp increase at 4MHz
110 6 RGB Beam limit OFF, Woofer ON, Sharp increase at 3MHz

111 7 RGB Beam limit OFF, Woofer ON, Sharp increase at 4MHz

Default 3

Option digit 3:

Binary Dec Function Default

000 0 System BG OFF, System I OFF, System M OFF.
001 1 System BG OFF, System I OFF, System M ON.
010 2 System BG OFF, System I ON, System M OFF.
011 3 System BG OFF, System I ON, System M ON.
100 4 System BG ON, System I OFF, System M OFF.
101 5 System BG ON, System I OFF, System M ON.
110 6 System BG ON, System I ON, System M OFF.

111 7 System BG ON, System I ON, System M ON.

Default 7

Option digit 4:

Binary Dec Function Default

000 0 Only AV1
001 1 AV1 +AV2
010 2 Only AV1
011 3 AV1 + AV2 + AV3
100 4 AV1 + S-VHS
101 5 AV1 + AV2 + S-VHS
110 6 AV1 + S-VHS

No
Default

1 2 3 4 5 6 7 8 9 A
1 3 7 1 4 0 4 6 * *

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111 7 AV1 + AV2 + AV3 + S-VHS

Option digit 5:

Binary Dec Function Default

000 0 R/B gain =0.56, GAMMA ON , SKYWORTH game OFF
001 1 R/B gain =0.56, GAMMA ON , SKYWORTH game ON
010 2 R/B gain =0.56, GAMMA OFF , SKYWORTH game OFF
011 3 R/B gain =0.56, GAMMA OFF , SKYWORTH game ON
100 4 R/B gain =0.83, GAMMA ON , SKYWORTH game OFF
101 5 R/B gain =0.83, GAMMA ON , SKYWORTH game ON
110 6 R/B gain =0.83, GAMMA OFF , SKYWORTH game OFF

111 7 R/B gain =0.83, GAMMA OFF , SKYWORTH game ON

Default 4

7

Option digit 6:

Binary Dec Function Default

000 0 PIF = 38.0MHz , No Signal Auto OFF, Normal gain Tuner
001 1 PIF = 38.0MHz , No Signal Auto OFF, High gain Tuner
010 2 PIF = 38.0MHz , No Signal no Auto OFF, Normal gain Tuner
011 3 PIF = 38.0MHz , No Signal no Auto OFF, High gain Tuner
100 4 PIF = 38.9MHz , No Signal Auto OFF, Normal gain Tuner
101 5 PIF = 38.9MHz , No Signal Auto OFF, High gain Tuner
110 6 PIF = 38.9MHz , No Signal no Auto OFF, Normal gain Tuner

111 7 PIF = 38.9MHz , No Signal no Auto OFF, High gain Tuner

Default 0

Option digit 7:

Binary Dec Function Default

000 0 External SIF, QSS ON, Menu line ON
001 1 External SIF, QSS ON, Menu line OFF
010 2 External SIF, QSS OFF, Menu line ON
011 3 External SIF, QSS OFF, Menu line OFF
100 4 Internal SIF, QSS ON, Menu line ON
101 5 Internal SIF, QSS ON, Menu line OFF
110 6 Internal SIF, QSS OFF, Menu line ON

111 7 Internal SIF, QSS OFF, Menu line OFF

Default 4

Option digit 8:

Binary Dec Function Default

000 0 SKYWORTH picture OFF, No Blue Background, English OSD

only

001 1 SKYWORTH picture OFF, No Blue Background, English /

Chinese OSD
010 2 SKYWORTH picture ON, English OSD only
011 3 SKYWORTH picture ON, English / Chinese OSD
100 4 SKYWORTH picture OFF, No Blue Background, English OSD

only
101 5 SKYWORTH picture OFF, No Blue Background, English /

Chinese OSD
110 6 Customer LOGO ON or Blue Background, English OSD only

111 7 Customer LOGO ON or Blue Background, English / Chinese

OSD

Default 0

9. Customer LOGO
The TV set art allow to display the Customer LOGO from 1 to 9 digit Character during Power
on or No signal.
There is two method to set the Customer LOGO on.

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9.1 Go to the function set menu (there are two ways;)
a. Press CH+(PROG+) key and CH-(PROG-) key on the control board at the same time

and switch on power switch, then go to the function set menu.

b. After TV is on, press "factory" key (See Note 1) twin then go to the function set

menu.

9.1.1 Press the AV button to toggle between LOGO and Option Code

9.1.2 Press the below button for the difference function:
Recall : for the SKYWORTH LOGO display
Timer : for quick Blue background display.
Number 0 to 9: For no. of Character LOGO display.
Program + /- : Select the LOGO Character for modify.
Volume +/- : Change of LOGO Character.
S.M. : Change the Blue Background mode or transparence mode.
P.M. : Change of the Character Color.

8

9.1.3 Press the AV button to toggle to the Option Code mode and press the “Factory” key
twin to exit.

9.2 Direct write the data to the EEPROM address.
Address
$199h No. of Character 00 to 09
$19C - $1A4hDisplay Character Refer table
$19Ah Character Color Refer table

$19Ah Color Data Charact

er

Data Charact

er

Data Charact

er
38h White FF Space 0C C 18 O
39h Red 01 1 0D D 19 P
3Ah Green 02 2 0E E 1A Q
3Bh Yellow 03 3 0F F 1B R
3Ch Blue 04 4 10 G 1C S
3Dh Magenta 05 5 11 H 1D T
3Eh Cyan 06 6 12 I 1E U
3Fh Black 07 7 13 J 1F V

08 8 14 K 20 W
09 9 15 L 21 X
0A A 16 M 22 Y
0B B 17 N 23 Z

COLOUR PURITY AND CONVERGENCE ADJUSTMENT

I. COLOUR PURITY ADJUSTMENT (See Fig.1)

BEFORE ANY ADJUSTMENTS DESCRIBED BELOW ARE ATTEMPTED,V-HIGH, B+ VOLTAGE
AND FOCUSING ADJUSTMENT MUST BE COMPLETED .

1. Place the TV receiver facing NORTH or SOUTH ,

2. Plug in TV receiver and turn it on .

3.Operate the TV receiver over 30 minutes.

1. Fully degauss the TV receiver by using and external degaussing coil

2. Receive a crosshatch pattern and adjust the static convergence control roughly.

3. Loosen the clamp screw of the deflection yoke and pull the deflection yoke towards you.

4. Enter into ADJUST MENU .set the values of C-R,C-G,C-B to “00”.

5. Adjust the purity magnets so that green field is obtained at the center of the screen.

6. Slowly push the deflection yoke toward bell of CRT and set it where a uniform green field is
obtained.

7. Tighten the clamp screw of the deflection yoke.

II. CONVERGENCE ADJUSTMENT (See Fig.1)

1. Receive a dotted pattern.

2. Unfix the convergence magnet clamped and align red with blue dots at the center of the screen by
rotating.(R,B)static convergence magnets.

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3. Align Red/Blue with green dots at the center of the screen by rotating (RB-G) static convergence
magnet.

4. Fix the convergence magnets by turning the clamped.

9

5. Remove the DY wedges and slightly tilt the deflection yoke horizontally and vertically to obtain the
good overall convergence.

6. Fix the deflection yoke by wedges.

7. If purity error is found, follow “PURITY ADJUSTMENT” instructions.

Purity Magnet
RB-G RB

Magnet Clamper

Static Magnet

(FIG.1)

10

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