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3. REPLACEMENT OF MEMORY IC 

 
1. MEMORY IC. 

This TV uses memory IC. In the memory IC are memorized data for correctly operating the video and deflection 
circuits. 
 

2.  PROCEDURE FOR REPLACING MEMORY IC 

(1) Power off 

Switch the power off and unplug the power cord from AC outlet. 

(2) Replace IC 

Be sure to use memory IC written with the initial data values. 

(3) Power On 

Plug the power cord into the AC outlet and switch the power on. 

(4)  Check and set SYSTEM default value: 

1) Press “MUTE” 

Æ

 “DISPLAY” 

Æ

 “PICTURE“ 

Æ

 “DISPLAY” 

Æ

 “MUTE” buttons in sequence to enter 

into factory status.   

2)  If the memory IC haven’t been written with the initial data, press [] / [Program-] to select item 

INIT and press [] / [VOLUME-] to start initialize memory IC. 

3)  Check the setting value of the SYSTEM default value of Table below. If the value is different, select 

items by [] / [Program-] keys and set value by [] / [VOLUME-] keys. 

4)  Press “EXIT” button to return to the normal screen. 

 

4. SERVICE ADJUSTMENT 

 

Specific operation: use remote controller   
Press “MUTE” 

Æ

 “CALL” 

Æ

 “-\--“ 

Æ

 “CALL” 

Æ

 “MUTE” buttons in sequence to enter into factory mode. 

Press [] / [Program-] to select items and press [] / [VOLUME-] key, to make data adjustment 
of corresponding factory menus. 

Press “EXIT” key to exit factory mode. 

 

Focus adjustment 

1.  Receive a crosshatch signal. 
2.  While watching the screen, adjust the FOCUS VR on the FBT to make the vertical and horizontal lines as 

fine and sharp as possible. 

 

Geometrical adjustment 

       

Receive PAL standard complete pattern signal. 
Adjustment steps

 

a)  Adjust VSL, to the centre horizontal line just appears from half bottom shadow. 
b)  Adjust VAM, to get 92% of vertical picture contents would be displayed on CRT. 
c)  Adjust VSH, the centre horizontal line corresponds to CRT vertical centre. 
d)  Adjust SCL, to the linearity of P card field is in proper condition. 
e) Adjust

 

HSH, to get the picture horizontal centre correspond to CRT horizontal centre. 

    Receive NTSC signal and repeat above adjustment. 

 

AGC Adjustment 

Receive 60dB

μ

 (1mV) VH colour bar pattern signal. 

Select TOP item. 

 

Adjust value, to noise reduce gradually and just disappeared point. 

 

CRT cut off and white balance adjustment 

a)  CRT cut off adjustment 

1.  Select item VG2B, then adjust value to 32. 
2.  PRESS “0” key, when the screen shows”VG2” adjust the SCREEN control on Fly back transformer to 

make the screen show alternating flashing characters of “INSIDE HIGH      INSIDE LOW”.

   

b)  White balance adjustment 

1. Receive a Black and White pattern. 
2. Adjust WRP, WRG, WRB items to get colour temperature 9300K 

±

3 JND. 

Summary of Contents for NS-F20C

Page 1: ...COLOUR TELEVISION SERVICE MANUAL Models NS F20C Edition 2007 3 1...

Page 2: ...CONTENTS 1 Safety precautions 3 2 TV block diagram 4 3 Replacement of memory IC 5 4 Service adjustment 5 5 ICs functional description 10 6 Test point waveform 10 7 All ICs voltages 10 2...

Page 3: ...t 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 groun...

Page 4: ...4 2 Block diagram TDA8377 PS N3 2 series with mono intercarrier sound demodulator...

Page 5: ...ata adjustment of corresponding factory menus Press EXIT key to exit factory mode Focus adjustment 1 Receive a crosshatch signal 2 While watching the screen adjust the FOCUS VR on the FBT to make the...

Page 6: ...ode drive level 31 AGC IF AGC speed VG2B VG2 Brightness IFO Off set IF demodulator 5 Picture preset 1 0CON Listen Contrast 0 A 0BRI Listen Brightness 0 A 0COL Listen Colour 50 A 0SHP Listen Sharpness...

Page 7: ...1 Enable 0 EA Bit 2 FMWS 1 Enable 0 EA Bit 1 RESERVE 1 Enable 1 EA Bit 0 AVL 1 Enable 1 EA 3 OP3 Bit Function Description Preset Remark Bit 7 TDA8377 1 Enable 1 EA Bit 6 16 9 1 Enable 0 EA Bit 5 RESER...

Page 8: ...I 2 C bus data line TUNING 4 tuning Voltage Vt PWM output KEY 5 Control keys input SYSTEM 6 TV system control VOL 7 Sound Volume control PWM output MUTE 8 Sound mute output VSSC P 9 Digit ground for...

Page 9: ...supply of TV processor 3 3 V VPE 55 Ground VDDC 56 Digital supply to core 3 3 V OSCGND 57 Oscillator ground supply XTALIN 58 Crystal oscillator input XTALOUT 59 Crystal oscillator output RESET 60 Grou...

Page 10: ...DA8377 PIN38 5Vpp 0 9Vpp CRT KB CRT KG CRT KR 95Vpp 95Vpp 95Vpp H H H 7 IC voltages TDA8377 PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 V 0 3 8 3 6 3 3 3 5 4 4 5 1 1 8 0 0 18 0 17 0 2 3 8 5 3 PIN 17 18...

Page 11: ...5 1 3 3 5 TDA8357 PIN 1 2 3 4 5 6 7 8 9 V 0 8 0 7 16 6 9 0 43 7 2 0 3 7 2 AN 7522N PIN 1 2 3 4 5 6 7 8 9 10 11 12 V 10 4 4 0 4 4 2 75 1 4 0 1 4 0 35 4 4 0 4 4 24C08 PCF8598 PIN 1 2 3 4 5 6 7 8 V 0 0...

Page 12: ...screen Fig 3 8 Move the deflection yoke forward and fix the position of the deflection yoke so that the whole screen will become green 9 Insert the wedge to the top side of the deflection yoke so that...

Page 13: ...nvergence DYNAMIC CONVERGENCE ADJUSTMENT 13 1 Move the deflection yoke up and down and overlap lines in the periphery Fig 2 2 Move the deflection yoke left to right and overlap the lines in the periph...

Page 14: ...TZJ5 1B DZ102 63V 0 1 F C101 1 6W 68K R261 1N4148 VD217 1 6W 9 1K R260 1 6W 1K R227 1 6W 9 1K R262 B4 12V C214 104 SYSTEM 1W 33 R110 LGA0203 100 L102 SDA SCL 1 6W 22 R103 SPEAKER SPEAKER INPUT INPUT 2...

Page 15: ...Sincere Forever 15...

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