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SERVICE MANUAL

1. HORIZONTAL amp VERTICAL PROCESSOR SECTION H SYNC V SYNC OUTPUT OUTPUT V L 25V 100 P 451K KME 12v KMG 50K 1 e E 479 16 5 50V KA rh KME KMG J 28 KMG M153 4 14 17 16 19 o7 ole JUMPER lj 221pF TS NPO 18 301 r 1 6W TDA91 2C 220 FBT MEE 8 is OUTPUT 5 16 M223 1 3 2 11 12 56 S 4 1492 LASS 2 2K 4 1 6W 68 d isspr 102pF 62K 10K F 100K F 2 iz P P P P KME KMG IC301 TDA9102C oscillates with embedded OSC outputs vertical and horizontal frequency in free running and even though SYNC is not supplied from outside it can operate IC301 supplies 12V voltage to Pin 20 to drive it With Pin 1 and Pin 2 in free running horizontal oscillation frequency is determined and with R313 and C309 free running frequency is determined Pin 3 compares and matches SYNC phase input from outside and phase of embedded OSC and it performs mainly with 8315 C307 C308 R314 and R312 and adjusts DC level with VR301 Pin 4 input terminal of horizontal SYNC is compatible with TTL and always triggers negative 19 KORTEK Corporation Pin 5 supplies sync input from outside to Pin 5 through embedded
2. KME KMG 5 gt i A 2 DAST 1 6W 6 8K 134 x 14 1 114 5 1V zes AST gt r g 1 1 L 6W 390 j D 2 KME KMG 107 enzat ol ese H SYNC 16201 ak 74HC86 acd 4BWpF E B 54V ine Fags 3 5 wd gt ASA 479 1 5 7 1N4148 1 6W 2 2K 7 T 2 10 50V P 1 6W 15M v sync H syne This SYNC control circuit converts SYNC to maintain constant level is always input regardless whether SYNC is input or not For the function the circuit is composed of chip embedding four exclusive or gate circuits Pin 14 is a terminal supplying Vcc for driving chip Pin 1 2 4 5 9 10 12 and 13 are SYNC input terminals Pin 3 6 8 and 11 are output terminals for details see FUNCTION TABLE FUNCTION TABLE EACH GATE IN PUT OUT PUT Pin 1 5 10 12 Pin 2 4 9 13 Pin 3 6 8 11 L L L H H H L 21 KORTEK Corporation 6 10 VERTICAL OUTPUT CIRCUIT SECTION VERTICAL OUT PUT CIRCUIT SECTION ee 1 220 35V KME KMG 031 19PIN amp IC501 1 6W pue 27K TDA8172
3. 45 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 314 WAFER FA 0640 08 CN950 CN950 CN950 315 WIRE LEAD BLACK 40mm 1007 424 ZD201e C422 46 KORTEK Corporation KT 1903NA UR Parts list of KT 1903NA UR different from KT 1903NA ST NO DESCRIPTION SPECIFICATION LOCATION NO 1 JUMPER WIRE 7mm C318 2 RESISTOR CARBON 1 6W 330 J R210 3 RESISTOR CARBON 1 4W 130K F R454 4 COIL MAIN TRANS KTV 4042A 19NA5 53V T101 5 CAPACITOR AC EPOXY 250VAC 102pF K Rear attachment of IC101 6 CAPACITOR AC EPOXY 250VAC 471pF K C103 C104 7 POSISTOR PDGS69RONSK PH101 8 IC C MOS HD74LS86P IC201 9 RESISTOR CARBON 1 6W 10K F R113 ZENER DIODE R113 10 RESISTOR METAL 1 2 2 J R510 POWER SAVING PCB POWER SAVING PCB R126 12 RESISTOR CARBON 1 6W 75 F R901 R902 R903 13 RESISTOR CARBON 1 6W 39K F R911 14 CAPACITOR CERAMIC 50V 331pF SL J C929 C930 C935 15 RESISTOR CARBON 1 6W 560K J R924 16 RESISTOR CEMENT 7W 1 2K F R928 R930 R937 17 WAFER LW 0640 06 CN901 18 SILICON GREASE YG6111 19 HARNESS 12PIN COLOR 650 mm CN205 20 JJUMP WIRE 7 5mm 950 J 950 J 950 21 PCB CEM 1 90X72mm 22 PCB CEM 1 23 32 23 TR IRF9630 Q1 24 RESISTOR CA
4. Tek 5MS 5 21 Acqs 41 i 69 28 Display 69 6mV Style 21 1 Vectors Dots vector 1 Accumulate s00ms 4 Accumulate s00ms 20109 M Chr 7 6 8mV Style Readout Graticule Format Intensity Options Full YT Tek 5 5 5 118 Acqs i 34 6mY Display B 34 8 Style POSH Vectors Dots Vector Accumulate 00115 4 pot Accumulate DE i ET 500115 ami tomy 0 ops Chi 6 8mv Style Readout Graticule Format Intensity Options Full YT 2 1C101 0880 PIN 5 INPUT WAVEFORM Tek SOE 10 5 5 28 Acqs 92 4mv Cursor 92 8 Function Paired M Sps chi 7 24m GE 20 os 1 sec Hz 4 V SYNC WAVEFORM Tek ACTE 10 5 5 2 Acqs 59 88 Hz Cursor 1 333 3 Hz Function Paired 3 8 20 i M sms cht r 24 H i Time Function Units RED AE 6 VIDEO IN PUT WAVEFORM Tek KODE 5MS s 156 Acqs t T 1 i A 32 4 1 Display 32 6MV Style RE Vectors Dots Vector Accumulate 500ms 4 Dot 1 amp ccumulate 00ms 6 8mV Style Readout ME Options M 10 5 Graticule Full YT Form
5. 12 KORTEK Corporation 6 GENERAL THEORY OF OPERATION 6 1 BLOCK DIAGRAM Above is the block diagram of the monitor as a whole Each major section is presented in a block The individual circuit that makes up the section is covered later and is not shown here This simple block diagram will allow you a fundamental understanding of the complete monitor This will help when covering the sections individually The process from video signal to video display starts with the video signal generated from the source The signal is composed of information that is fed into various sections of the monitor the following diagrams are based on 17 19 VGA auto bias monitor and are included for reference only Actual circuit may be different Please see update schematic and parts list enclosed 6 2 VIDEO DRIVE SECTION VIDEO DRIVE SECTION 1 UF 5 KME KMG s T 46 18UF 50V KME KMG R DRIVE OUTPUT J 3 4 G DRIVE OUTPUT B DRIVE OUTPUT CONT 100UF 25V KME KMG 1 0 13 KORTEK Corporation Video signal 0 7V PP supplied from CN901 Pin 2 BLUE 4 GREEN 6 RED is supplied to 901 Pin 4 6 8 through C902 C903 905 901 performs VIDEO PRE AMP and its amplitude is determined by DC BIAS of Pin 1 2 3 Pin 9 Contrast controls its output video level Video signal passing through the DCBIA
6. 34 KORTEK Corporation 13 0403 WAVEFORM KT 1903NA Tek SONE 5 5 5 38 Acqs i F i 692mV Display 696mv Style zm Vectors Dots Vector Accumulate 500ms pou i bem 200mv M 10 8 1 EMV Style Readout Graticule Format Intensity Options Full YT 15 VIDEO IN PUT WAVEFORM Tek ECH 5MS s 156 Acqs F 1 i A 32 4 1 Display 32 6my Style AS Vectors Dots Vector 1 Accumulate 500ms pote SET Ch 10 M 10hs 6 8 1 Style Readout Graticule Format Intensity Options Full YT FULL WHITE 17 VIDEO CATHODE OUT WAVE FORM Tek 5 5 5 35 5 WENA 3 692mv Display 10 696mv Style GE Vectors Dots Vector Accumulate 500115 E pot Accumulate Bp 200 M 1085 ChT smv Style Readout Graticule Format 222 Options Full YT 14 0404 WAVEFORM Tek 5MS s 31 Acqs t 692mv Display 696mv Style SRE Vectors Dots vector Accumulate 500ms peti Accumulate E0700 ee 200 POM 1088 1 7 smv Style Readout Graticule Format MS Options Full
7. COLOR CRT MONITOR DOC NO 5 2004 02 02 REV 0 REV DATE KT 1403NA korfek KORTEK CORPORATION SERVICE manuat KT 1903NA KT 1703NA CONTENTS 1 PRECAUTIONS 2 PRODUCT SPECIFICATIONS 3 OPERATING INSTRUCTIONS 4 ADJUST MENT 5 BLOCK DIAGRAM 6 GENERAL THEORY OF OPERATION 7 TROUBLE SHOOTING GUIDE 8 WAVE FORM 9 BILL OF MATERIAL 10 SCHEMATICS 10 10 12 13 26 33 36 51 KORTEK Corporation 1 PRECAUTIONS 1 1 SAFETY PRECAUTIONS WARNINGS Service should not be attempted by anyone unfamiliar with the necessary precautions on this monitor The following precautions are necessary during servicing 1 For continued safety do not attempt to modify the circuit board 2 Disconnect the AC Power before servicing 3 When the Monitor is operating do not touch any heatsink on the Chassis as it is self heated 1 1 1 FIRE 8 SHOCK HARZARD 1 During servicing pay attention to the original wires whether it is uncoated or undressed especially the wires in the high voltage circuit section If there is any uncoated or melted wire is found then please do not try to replace the related parts and wait for the q
8. 122 HARNESS 7P RING CORE TO SOCKET CN204 123 HEAT SINK JS 23 1 35mm Q901 Q902 Q903 124 HEATSINK FOR D401 HOR 592 40mm D401 125 HEATSINK FOR FBT A 3 85mm T402 126 HEATSINK FOR IC101 POW J S 21 2 40mm IC101 127 HEATSINK FOR IC501 VER 5 21 1 50mm CUT IC501 128 HEATSINK FOR Q102 JS 100 30mm Q102 129 IC TDA9102C IC301 130 IC KA358A OP AMP IC401 131 IC TLP721 D4 GB IC102 132 IC 250880 800V 8 IC101 133 IC 74LS86 TTL IC201 134 IC TDA8172 VERTICAL IC501 135 IC MC14538BCP IC202 136 IC KA2141 IC901 137 IC KIA2904 SMD TYPE IC902 138 IC KIA2904 SMD TYPE IC950 950 IC950 139 JUMP WIRE 5mm 416 140 JUMP WIRE 7 mm C318 141 JUMP WIRE 7 5mm 1950 950 950 142 PCB CEM 1 110 82 5 mm 143 PCB CEM 1 107 5 46 5mm 1 6t 144 PCB CEM 1 FOCUS 105 55 1 6T 145 PCB CEM 1 MAIN 246 196mm 1 6t 146 POSISTOR DP3BG140M12 PH101 147 RELAY DY1S 12H RE702 148 RESISTOR CEMENT 7W 1 2KF R928 R930 R937 149 RESISTOR CARBON 1 2W 47 R203 40 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 150 RESISTOR CARBON 1 2W 150 R508 151 RESISTOR CARBON 1 2W 270 R117 152 RESISTOR CARBON 1 2W 120K R116 153 RESISTOR CARBON 1 4W 1 5 8507 154 RESISTOR CARBON 1 4W 22 R405 155 RESISTOR CARBON 1 4W 27 R109 R425 156 RESISTOR CARBON 1 4W 39 R512 15
9. 3 8 ri MSS MSS 125v MZ 47 A 8 ST iss 150 C2316 630V 758 2476 25 P P O 12v 3283 KME KMG 2 NPN 50K i 1N4937 22 160v ro 470 2 2 1 184743 NPN A1023 KME KMG 066 1 100 4 6 KME KMG si z 5 b 390 1N493 Sh CONT B 10K 2 2K Horizontal drive receives pulse from TDA9102C Pin 6 varies according to frequency and applied to Q401 base Then Q401 repeats on and off according to the pulse At this time pulse is generated in T401 and operates T401 When T401 operates pulse separated from the secondary side of T401 can drive horizontal so that it supplies pulse to Q402 base and repeats on and off by pulse and the operation can drive FBT C402 and C403 generates pulse and supplies it to horizontal deflection and 900V 1000V Vcp voltage is applied to T402 Pin 1 and this voltage varies with voltage supplied to T402 Pin 2 this voltage is supplied from SMPS according to horizontal frequency The supplied Voltage is raised in T402 and output as high voltage screen voltage and focus voltage V R401 horizontal raster position control VR receives voltage from T402 Pin 3 and voltage from Pin 4 and varies DC voltage with Q403 and Q404 to move horizontal raster toward the right and left side 23 KORTEK Corporation 6 12 KT 1903NA adjustment method 1 B voltage adjustment method 1 Measuring terminal D114 CATHO
10. NG 4 OK CHANGE 501 NG S CHANGE ZD201 2 28 KORTEK Corporation KT 1903NA 8 4 VERTICAL DEFLECTION PROBLEM VERTICAL DEFLECTION PROBLEM CHANGE D501 CHANGE IC501 CHECK CHANGE P CHECK amp CHANGE D110 IC501 NG CHANGE R510 NG CHANGE CDT DY CABLE 29 KORTEK Corporation KT 1903NA 7 5 HORIZONTAL DEFLECTION PROBLEM HORIZONTAL DEFLECTION PROBLEM OK CHANGE pere IC301 NG OK 4 OK CHANGE 0401 NG OK CHECK amp CHANGE 401 0402 NG CHANGE FBT NG CHECK amp CHANGE R402 R455 OK CHECK DY CABLE OK 30 KORTEK Corporation KT 1903NA 7 6 X RAY FROTECTION PROBLEM X RAY PROTECTION PROBLEM CHANGE IC202 CHANGE C303 OK CHECK amp CHANGE R324 NG CHANGE D301 NG ek CHANGE FBT OK 31 KORTEK Corporation KT 1903NA 7 7 AUTOBIAS PROBLEM AUTO BIAS PROBLEM N G OK CHANGE a BK 1 902 NG OK CHECK amp CHANGE 1 950 NG 32 KORTEK Corporation KT 1903NA 80000 00 1 1C101 0880 PIN 1 OUTPUT WAVEFORM Tek SONE 5 5 5 46 Acqs E F i 4 6 Cursor 4 64 V Function off gx m Time Function oo 1 sec Hz 3 H SYNC WAVE FORM
11. STARE NKO CAMO Boo 9 SO 3 Q o o 2 J950 RE ee gt Xe 2 1998 11 24 SOCKET PCB REV A 2 2 1 15 PIN SIGNAL CABLE CONNECTOR 2 2 2 PIN DESCRIPTION PIN_NAME A PIN_NAME RED VIDEO NC GREEN VIDEO SHIELD GND KORTEK Corporation 2 3 TIMING CHART HORIZONTAL VIDEO BC D HORIZONTALSYNC pe F VERTICAL VIDEO 00 NO 1 2 3 4 MODE IGT IBM VGA IBM VGA IBM VGA RESOLUTION H 640 640 720 640 V 480 350 400 480 SYNC POLARITY H POSI POSI NEGA NEGA V POSI NEGA POSI NEGA H FREQUENCY 31 469 31 469 31 469 31 469 PERIOD 31 777 31 777 31 777 31 777 SYNC 3 813 3 813 3 813 3 813 B P 1 907 1 094 1 907 1 907 ACTIVE 25 422 25 422 25 422 25 422 V FREQUENCY 59 941 70 087 70 087 59 941 PERIOD 16 683 14 268 14 268 16 683 SYNC 0 064 0 064 0 064 0 064 F P 1 049 1 907 1 080 1 049 ACTIVE 15 253 11 122 12 711 15 253 FIXEL FREQUENCY 25 175 25 175 28 322 25 175 INTERACE NO NO NO NO KORTEK Corporation 3 OPERATING INSTRUCTIONS 3 1 LOCATION FUNCTION OF CONTROL PCB ASS Y d ji e KT XX 3N HA27 O lt O e AUTO BIOS CN205 J2 12 10 3 1 i5 gt x e J4 J3 R434 e om wo 8515 0 OVR304 R308 VR501 R460 V
12. WHITE BALANCE 8 LUMINANCE X 281 20y 311 20 Y 10 3F L 56 5F L KORTEK Corporation 2 2 PCB DIMENSIONS 1 MAIN PCB 6471 31 2 8117 R116 C303 R471 Cw op o cite 20381 J149 6 9 so 8211 o lt E o pj o Quo o 5 80165 8 f M BAG 8 8 8 6 6 8429 6314 8 5 3 5 4 Le 3 c oi 80104 5111 6150 0119 0112 9 NOSZ YGL S L CN102 N FOR CONTINUED PROTECTION AGAINST RISK OF FIRE CAUTION ee ONLY WITH SAME TYPE AND RATING OF FUSE CN101 9114 es 9 Quo 5255 20202 J132 BT 12 13 CN206 AUTO 92 33 CN207 NOR 8 O VYV O 8292 8429 50001 8 8 e ER 7175 o 5 4 9 6 5 oo 8 2 9 0 lt gt 0 o 8 oci so 58 of w o 59 7 q x al e CJC 0 lt R107 CN204 IN 2 9
13. WIRE 10 mm 916 925 913 19 JUMP WIRE 7 5mm 950 J 950 J 950 20 JUMP WIRE 8 mm R720 J UMPER WIRE 10 mm R435 R436 COIL INDUCTOR 100uH ALO3 TYPE J115 116 COIL INDUCTOR 4 7uH ALO3 TYPE J 175 36 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 21 HARNESS 190mm 2P 3P 38K CN701 22 160mm 4 CUTTING 23 BEAD CORE ATS3560L 3 5 6mm BD101 BD401 J 102 24 CABLE TIE SJ CT 100mm 25 CAPACITOR CERAMIC 50V 102pF C906 C907 C908 26 CAPACITOR CERAMIC 50V 103pF F Z C901 C910 C911 C912 27 CAPACITOR CERAMIC 50V 104pF F z C916 28 CAPACITOR CERAMIC 50V 221pF SL J C918 C919 29 CAPACITOR CERAMIC 50V 561pF SL J C953 C953 C953 30 CAPACITOR CERAMIC NPO 50 101 pF J C417 31 CAPACITOR CERAMIC NPO 50 V 221 pF J C305 32 CAPACITOR CERAMIC NPO 50 V 271 K J C109 33 CAPACITOR CERAMIC NPO 50V 331pF J C929 C930 C935 34 CAPACITOR ELECTROLYTIC 16 V 470 uF KME KMG C123 C126 35 CAPACITOR ELECTROLYTIC 25 V 470 uF KME KMG C301 C406 C407 36 CAPACITOR ELECTROLYTIC 30 V 10 uF OS CON C420 37 CAPACITOR ELECTROLYTIC 35 220 UF KME 504 38 CAPACITOR ELECTROLYTIC 35 1000uF KME 122 503 C119 39 CAPACITOR ELECTROLYTIC 35 2200uF KME KMG C507 40 CAPACITOR ELECTROLYTIC
14. despite of that there are a few differences due to the conditions of voltage supplied to GRID 1 GRID 2 and GRID 3 and 5 heat electrons generally move to CRT face and current is generates to the opposite direction The current appears on the surface of CRT RED cathode SUB PCB Pin 4 is connected to RED cathode and current and voltage passing through R962 change in Q953 emitter This changed current appears in the form of wave signal 3953 collector and sent to IC950 to be amplified IC950 amplifies the signal at rate of R956 R957 and R955 and sends it to IC950 Pin 3 for the second amplification Second amplification of 1 950 is made at rate of R952 and R964 and pulse is converted to DC level by ZD950 and C952 The converted DC voltage is sent to SUB PCB Pin 6 by controlling Q951 Q952 and Q950 and controls Q953 base When the voltage of Q953 base changes emitter voltage changes and controls emission of heat electrons from CRT cathode This operation is made through feedback loop and maintains a constant value with repeat 6 6 PULSE GENERATOR CIRCUIT PULSE GENERATOR CIRCUIT 87187 Pulse generator circuit supplies control power to auto bias circuit The circuit makes and supplies pulse in order for auto bias circuit to operate only during blanking period for preventing error For detailed timing chart see waveform of Circuit Diagram The circuit is supplied horizontal amp vertical blank pulse through R917 and cont
15. 1 2W 100 715 218 RESISTOR CARBON 1 6W 1K J R724 219 RESISTOR CARBON 1 6W 4 7K J R723 220 RESISTOR CARBON 1 6W 15K J R721 R722 221 RESISTOR CARBON 1 6W 75 F R901 R902 R903 222 RESISTOR CARBON 1 6W 100 F R906 R914 8927 8929 R932 223 RESISTOR CARBON 1 6W 390 F R905 R915 R939 224 RESISTOR CARBON 1 6W 32K F R911 225 RESISTOR CARBON 1 6W 33K F R913 R940 226 RESISTOR CARBON 1 6W 100K F R909 R910 R912 227 RESISTOR CARBON 1 6W 330 J R945 R946 R947 228 RESISTOR CARBON 1 6W IK J R904 229 RESISTOR CARBON 1 6W 2 4K J R916 230 RESISTOR CARBON 1 6W 3 3K J R925 231 RESISTOR CARBON 1 6W 9 1K J R920 232 RESISTOR CARBON 1 6W 27K J R908 233 RESISTOR CARBON 1 6W 100K J R926 234 RESISTOR CARBON 1 6W 270K J R935 235 RESISTOR CARBON 1 6W 560K J R924 236 RESISTOR CARBON 1 6W 1 J R917 237 RESISTOR CARBON 1 6W 4 7M F R948 238 RESISTOR CARBON 1 6W 10M J R931 R933 R936 239 RESISTOR CARBON 1 6W 15M J R934 240 RESISTOR CARBON 1 6W 9 1K F R964 R964 8964 241 RESISTOR CARBON 1 6W 20K F R951 R951 R951 242 RESISTOR CARBON 1 6W 33K F R952 R952 R952 243 RESISTOR CARBON 1 6W 1M F R956 R956 R956 244 RESISTOR CARBON 1 6W 680 J R957 R957 R957 245 RESISTOR CARBON 1 6W 1 8K J R962 962 R962 246 RESISTOR CARBON 1 6W 100K J R961 R961 R961 247 RESISTOR CARBON 1 6W 4 7M F R950 R959 R960 8960 R960 248 RESISTOR CARBON 1 6W 15M J R958
16. 5 mm 83 PCB CEM 1 107 5 46 5mm 1 6t 84 RESISTOR CARBON 1 4W 3 3K J R433 85 RESISTOR CARBON 1 4W 10K J R427 86 RESISTOR CARBON 1 4W 39K J R307 87 RESISTOR CARBON 1 4W 47K J R310 88 RESISTOR VARIABLE 20KB RVM630V VR407 89 RESISTOR CEMENT 5W 120 R404 90 RESISTOR CARBON 1 6W 75K F R952 R952 R952 91 RESISTOR CARBON 1 6W 220 F R983 92 RESISTOR CARBON 1 6W 470 J R980 50
17. 6W 8 2 R922 281 RESISTOR CARBON 1 6W 560K R921 R923 44 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 282 SCREW TAPPING TP3 8mm CUT 283 SCREW TAPPING TP3 12mm CUT 284 SILICON PAD 20 25mm 0 45t FOR IC101 285 SOCKET PCS 626 01 PCS626 01 286 SOCKET PCB COVER 82 5 110mm 287 SURGE ABSORBER BSD 201L 5 3902 SG903 SG904 288 SURGE ABSORBER BSD 201L SG950 SG950 SG950 289 THERMISTOR 8D13 TH101 290 TRANS HDT 22188 T401 291 TRANS MAIN KTV 4042A 15NA T101 292 TRANSISTOR A1023 Q404 293 TRANSISTOR A1271 Q502 294 TRANSISTOR B601 Y Q102 Q408 295 TRANSISTOR BU2520DF Q402 296 TRANSISTOR C2316 Q401 297 TRANSISTOR C3198 Q201 Q303 Q405 298 TRANSISTOR C3203 Q403 Q501 299 TRANSISTOR C3206 Q103 300 TRANSISTOR C3503 Q406 Q407 301 TRANSISTOR C 945YC Q710 Q711 Q712 302 TRANSISTOR 5042F Q904 303 TRANSISTOR 3503D Q901 Q902 Q903 304 TRANSISTOR 2N6517 0951 0951 0951 0952 0952 0952 305 TRANSISTOR 2N6520 Q950 Q950 Q950 Q953 Q953 Q953 306 WAFER YFW800 04 CN401 307 WAFER LW1143 02 FBT SYNC CN103 308 WAFER YW025 12 CONTROL CN203 309 WAFER 5267 03 H V SYNC CN201 310 WAFER 5267 02 DYNAMIC CN701 311 WAFER 5267 05 DYNAMIC CN702 CN205 312 WAFER 5267 06 01 CN901 313 WAFER 5267 07 01 CN902
18. CN402 Kaj lt gt 8192 Dee AN 285038 852 8 KEND o SR E 2 H 1 6 3V 6 Sev 4 CONTRAST 6 CLAMP 5 761 O0 so 1 99m o o A 1 mos 1552 0101 o 0497 gt matet o o 1124 9 9 C104 so OX 085 5 e 5 1126 N o o 2 E Bo ve 5 za SUB 3 T JE Dre 22 8 as SE quss f om o S NOR SHORT 5 D4080 0 S d e 9 S Sr ess J194 x n F101 o 6215 6 6 8452 e 988888 gt cies VR4 3 CN207 R333 g 88 7 faj Hod 69 29 ja GA ER 96 28 558 e gle 525 2522 5220 2 8 o As 0 lt 0 8282828 1 R502 GND ed E9 o o o o o 0402 Corporation 2 5 1064 5 GE BLK IC901 442 206 0 a
19. R958 R958 43 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 249 RESISTOR CARBON 1 6W 100 F R938 250 RESISTOR CARBON 1 6W 8 2K R922 251 RESISTOR CARBON 1 6W 560K J R921 R923 252 RESISTOR CARBON 1 6W 15K F R954 R954 R954 253 RESISTOR CARBON 1 6W 1M F R955 R955 R955 254 RESISTOR CARBON 1 6W 47K R963 R963 R963 255 RESISTOR CEMENT 5W 75 R404 256 RESISTOR CEMENT 5W 56 LEAD 45mm R406 257 RESISTOR CEMENT 5W 100 LEAD 45mm R511 258 RESISTOR METAL 1W 1 8 R125 259 RESISTOR METAL 1W2 R510 260 RESISTOR METAL 1W 56K J R102 261 RESISTOR METAL 2W 2 2 J R123 262 RESISTOR METAL 2W 12 R126 263 RESISTOR METAL 2W 1K J R429 264 RESISTOR METAL 2W 22K J R119 265 RESISTOR METAL 2W 68K J R108 266 RESISTOR VARIABLE 500B RVM630H VR101 267 RESISTOR VARIABLE 10KB RVM630H VR402 268 RESISTOR VARIABLE 50KB RVM630H VR301 VR302 VR303 VR401 269 RESISTOR VARIABLE 10KB 068C C303 270 RESISTOR VARIABLE 5KB 92H VR404 271 RESISTOR VARIABLE 10KB 92H VR405 VR406 272 RESISTOR VARIABLE 20KB 92H VR501 274 RESISTOR VARIABLE 50KB 92H VR305 275 RESISTOR VARIABLE 10KB 068C C303 276 SCR KA431AZ Q101 277 SCR MCR 100 6 Q301 278 SCREW PAN WASHER TP3 8 CUT Q901 Q902 Q903 279 RESISTOR CARBON 1 6W 100 F R938 280 RESISTOR CARBON 1
20. V DRIVE INPUT TAS IC501 amplifies sawtooth waveform output from TDA9102 Pin 15 and supplies it to deflection yoke IC501 uses Pin 5 to output the amplified wave 501 Pini receiving sawtooth waveform output from TDA9102 Pin15 amplifies and output it through amplifier embedded in chip and supplies it to reflection yoke The outputting terminal is composed of C505 C511 and R508 R507 Pin 2 is a terminal supplying reference voltage Pin 3 is pulse generator and Pin4 is used as GND Pin6 as B terminal of TDA 8172 device supplies 24V voltage and drives circuit It supplies current necessary for vertical deflection through C503 and D501 R508 and C511 is a circuit used for DAMPING to prevent current flowing in DY coil from distorting during switching 22 KORTEK Corporation 6 11 HORIZONTAL DRIVE 8 OUTPUT CIRCUIT SECTION HORIZONTAL OUTPUT CIRCUIT 50 1uF F H DY 2 680 d 175 4 i fi M47387 O H SIZE T qie radi amp 1402 22 5 o HOT 3 KFS 61619A C 26V T SW 75 pur BU2520DF m 3 a 822 a 1 1 KMG IT 6KV 185 gt 6301 P P 250v 8 0084 PIN16 7 E LK p E z H INPUT O 34 5 UF5404 1K 5 5w 100 15 14 NEN
21. interface and at this time according to capacitor value of C305 connected to Pin 5 pulse width is determined Pin 6 outputs horizontal output pulse and its range is from 27Khz to 70Khz Pin 7 20 is used as terminal supplying B of device Pin 8 receives feedback for pulse from No 6 terminal of FBT compares and detects it so that it operates in sequence of detected feedback to maintain high voltage constantly Pin 9 determines gradient of waveform in oscillation cycle of oscillator and is determined by C306 capacitor value Pin 10 controls H phase by adding or subtracting it with DC voltage and its circuit is composed of C308 R310 R309 and VR305 Pin 11 is used as GND of IC301 Pin 12 and Pin 18 terminal controlling vertical frequency is controlled with DC level and its circuit is composed of R318 C311 R317 R316 VR301 and R332 Pin 14 is used as input terminal of vertical SYNC and always receives negative signal Pin 15 is used as vertical output terminal Pin 16 is a terminal used to control the vertical size and its vertical size varies with DC level input to Pin 16 and is composed of C315 R307 R308 and VR304 Pin 17 controls vertical linearity according to DC level input to Pin 17 and is composed of 8305 C313 C302 8306 and VR303 Pin 19 is a terminal used to supply the reference voltage 20 KORTEK Corporation 6 9 SYNC CONTROL CIRCUIT SYNC CONTROL CIRCUIT 100 50V 5 1V KME KMG 47 1 2
22. terminals 5 Never touch any of the locked B voltage Do not apply AC power to the unit or any of its Assemblies unless all solid state heatsinks are correctly installed 6 Always connect a test instrument s ground lead to the instrument chassis ground before connecting the positive lead always remove the instrument s ground lead last KORTEK Corporation 2 Product Specifications 2 1 SPECIFICATION PARAMETER MIN TYP MAX UNITS OPERATING VOLTAGE 100 115 230 230 VAC OPERATING POWER 85 90 WATTS LEAKAGE CURRENT TO CHASSIS GND lt 0 40 0 45 mA AT250VAC 50 60Hz LINE NATU IN COMMON HI POT LINE NEUT IN COMMON lt 2 0 2 4 mA OPERATING TEMPERATURE 10 60 DEGREE REL HUMIDITY OPERATING 10 90 MAGNETIC SHIELD INTERNAL DEGAUSSING MANUAL TYPE VIDEO SIGNAL 0 7Vpp 75 Ohm MONITOR TERMINATIONS RASTER DIM ADJUST RANGE VERTICAL lt 190 gt 290 mm RASTER DIM ADJUST RANGE HORIZONTAL lt 300 gt 350 mm MODE 640 480 PINCUSHION ALL BRIGHTNESS 3 0 MIS CONVERGENCE CENTER 0 25 0 3 mm MIS CONVERGENCE CORNERS 0 35 0 45 mm VERTICAL SCAN RATE 60 70 Hz HOLD IN RANG 5 Hz SYNC 5V 74LS LEVELS 5 0 5 0 VOLTAGE LOW 0 0 0 0 0 6 VOLTAGE NON LINEARITY 5 HORIZONTAL SCAN FREQUENCY 31 2 31 4 31 6 Khz HOLD IN RANG 500 Hz SYNC POLARITY POSITIVE SYNC 5V 74LS LEVELS 5 0 5 0 5 0 VOLTAGE LOW 0 0 0 0 0 6 VOLTAGE NON LINEARITY 5
23. 2uF 4 7 5mm SRA C951 C951 C951 59 CAPACITOR ELECTROLYTIC 50V 10uF 5 7mm SRA C952 C952 C952 60 CAPACITOR EPOXY 250VAC 102pF M C103 C104 C112 C113 61 CAPACITOR EPOXY 1 KV 101 pF C117 C120 C925 62 CAPACITOR EPOXY 1 KV 471 pF C114 63 CAPACITOR EPOXY 1 KV 472 pF C106 64 CAPACITOR EPOXY 2KV 102pF C933 65 CAPACITOR MPE 100 224pF J C310 66 CAPACITOR MPP 250 824pF J C404 67 CAPACITOR MPP 250V 504pF J C712 68 CAPACITOR MYLAR 100 102pF J C316 C319 C405 69 CAPACITOR MYLAR 100 103pF J C312 C315 C502 Q202 C708 C920 70 CAPACITOR MYLAR 100 V 104pF J C304 C501 123 177 71 CAPACITOR MYLAR 100 V 154pF J C511 72 CAPACITOR MYLAR 100 V 223pF J C306 73 CAPACITOR MYLAR 100 V 224pF J C110 C505 74 CAPACITOR MYLAR 100 V 472pF J C430 75 CAPACITOR MYLAR 100 V 473pF C425 76 CAPACITOR MYLAR 100 683pF J C115 77 CAPACITOR P P 100 102pF J C206 C309 78 CAPACITOR P P 100 153pF J C308 C302 79 CAPACITOR 630 V 123pF C403 80 CAPACITOR P P 630 153pF C410 81 CAPACITOR P P 630 V 473pF J C111 82 CAPACITOR P P 1 6KV 682pF J C402 83 CAPACITOR X CAP PILKOR 250V 224pF BOX TYPE 101 102 84 CHASSIS 1 246 196mm 85 CHASSIS 2 196mm 86 COIL CHOKE C110R L403 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOC
24. 50 V 0 47uF KME C471 41 CAPACITOR ELECTROLYTIC 50 V 1 uF KME KMG C108 C311 C418 C472 42 CAPACITOR ELECTROLYTIC 50 2 2uF KME C307 43 CAPACITOR ELECTROLYTIC 50 4 7uF KME C419 C204 44 CAPACITOR ELECTROLYTIC 50 V 10 uF KME KMG C201 C202 C313 C415 C423 C429 C509 45 CAPACITOR ELECTROLYTIC 50 V 47 uF KME KMG C422 C506 C107 46 CAPACITOR ELECTROLYTIC 50 V 100uF KME KMG C203 C205 C414 C508 C510 47 CAPACITOR ELECTROLYTIC 100 V 1 uF BP KME C411 48 CAPACITOR ELECTROLYTIC 160V 22 uF KME KMG C408 49 CAPACITOR ELECTROLYTIC 200V 33 KME C116 C124 C413 50 CAPACITOR ELECTROLYTIC 200V 100 uF KME 118 C121 24 CAPACITOR ELECTROLYTIC 400V 220 uF KME KMG C105 52 CAPACITOR ELECTROLYTIC 25V 100uF KME KMG C917 53 CAPACITOR ELECTROLYTIC 50V KME C904 C915 C922 C706 C707 37 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 54 CAPACITOR ELECTROLYTIC 50V 10uF KME KMG C902 C903 C905 C914 55 CAPACITOR ELECTROLYTIC 200V 47uF KME 9 3 56 CAPACITOR ELECTROLYTIC 250V KME 923 57 CAPACITOR ELECTROLYTIC 100V 1uF BP KME C921 C928 C931 C934 58 CAPACITOR ELECTROLYTIC 50V 0 2
25. 7 RESISTOR CARBON 1 4W 47 R407 158 RESISTOR CARBON 1 4W 390 R408 159 RESISTOR CARBON 1 4W 470 R205 160 RESISTOR CARBON 1 4W 680 J R414 161 RESISTOR CARBON 1 4W R103 R201 R202 R401 R403 162 RESISTOR CARBON 1 4W 1 amp R402 163 RESISTOR CARBON 1 4W 2K J R505 164 RESISTOR CARBON 1 4W 2 2K J R118 R415 R432 165 RESISTOR CARBON 1 4W 2 4K J R419 166 RESISTOR CARBON 1 4W 3 6K J R409 167 RESISTOR CARBON 1 4W 4 7K J R207 R430 168 RESISTOR CARBON 1 4W 6 2K J R319 R431 169 RESISTOR CARBON 1 4W 10K J R209 170 RESISTOR CARBON 1 4W 12K J R329 R416 R418 171 RESISTOR CARBON 1 4W 22K J R306 R501 R504 172 RESISTOR CARBON 1 4W 39K J R451 173 RESISTOR CARBON 1 4W 43K J R422 174 RESISTOR CARBON 1 4W 51K J R305 175 RESISTOR CARBON 1 4W 56K J R428 317 176 RESISTOR CARBON 1 4W 100K J R324 R410 R417 R423 R424 177 RESISTOR CARBON 1 4W 150K J R318 178 RESISTOR CARBON 1 4W 180K J R454 179 RESISTOR CARBON 1 4W 560K J R120 180 RESISTOR CARBON 1 4W 1 2K F R208 181 RESISTOR CARBON 1 4W 1 5K F R411 182 RESISTOR CARBON 1 4W 3 3K F R315 41 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 183 RESISTOR CARBON 1 4W 4 3K F R506 184 RESISTOR CARBON 1 4W 5 6K F R503 185 RESISTOR CARBON 1 4W 6 8K F R313 R509 186 RESISTOR CA
26. ATION NO 87 COIL CHOKE 822 89 L401 88 COIL LINE FILTER LF 2828 L101 89 COIL LINEARITY 17 1 1402 90 COIL PEAKING 151uH BD103 BD104 91 COIL PEAKING 4 7uH ALO3 TYPE L901 L902 L903 92 COIL PEAKING 100uH ALO4 TYPE L904 93 COVER 107 5 46 5mm 94 DIODE 1N4937 600V D102 D103 D104 D114 D403 D404 D406 D501 95 DIODE EGP20C 150V 2A D111 96 DIODE RGP15J 600V 1 5A D110 97 DIODE 1N4002 D118 98 DIODE HER204 D112 99 DIODE RG4C D108 D109 D116 100 DIODE UF5404 D402 101 DIODE DD84 D401 102 DIODE 1N4148 ZD101 103 DIODE 1N4002 D705 104 DIODE 1N4148 D701 105 DIODE 1N4148 D901 D902 D903 D904 D908 D909 D910 106 DIODE FR107 D905 D906 D907 107 DIODE BRIDGE PBS406GU D101 108 DIODE ZENER 5 1V ZD201 ZD202 ZD203 109 DIODE ZENER 6 2V ZD103 110 DIODE ZENER 24V ZD401 ZD402 111 DIODE ZENER UZP 108 ZD301 112 DIODE ZENER 24V 0 5W ZD901 113 DIODE ZENER 24V 0 5W 2 3950 ZD950 ZD950 114 F B T KFS 61619 T402 BLACK WIRE CUTTING 115 FUSE UL CE 3 15L 250V 50T F101 TYPE 116 FUSE CLIP 51A F101 117 2 36mm CN101 CN102 GND 39 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 118 G TPIN 2 36mm GND 119 HARNESS 500mm 12P COLOR CN205 120 HARNESS 5P 5P 160mm 38 CN702 121 HARNESS 2P ORANGE RED 190mm 2 CN206
27. DE side 2 Adjusting V R V R101 3 Adjusting voltage 54 0 2V 4 Measuring condition AC 120 V 60 Hz CROSS HATCH PATTERN 5 Other voltage 6 2 0 1 122 0 5V 2 SCREEN voltage adjustment method 1 Measuring terminal C933 SCREEN 2 Adjusting V R FB T SCREEN V R 3 Adjusting voltage 550 5V 4 Measuring condition CROSS PATTERN 3 HIGH VOLTAGE adjustment method 1 Measuring terminal CRTANODE 2 Adjusting voltage 23 4 300 3 Measuring condition CROSS HATCH PATTERN Screen size at the full scan horizontal frequency 31 5 Khz 4 CONTRAST adjustment method 1 Measuring terminal center of screen 2 Adjusting V R V R402 V R406 V R407 3 Measuring condition SCREEN voltage 550 5V VIDEO input voltage 0 7V Screen brightness 15F L 55F L 4 Adjusting method To supply Window pattern by operation of SIGNAL SOURCE To adjust V R 402 for brightness into 55F L at the Max of V R 406 To adjust V R 407 for brightness into 15F L 24 KORTEK Corporation 5 Horizontal RASTER position adjustment 1 Adjustment V R V R401 2 Adjustment position center of screen 6 Check of coordinates value 1 Adjustment position center of screen measured as CA 100 in CRT face 2 Measuring condition After adjusting Back Roaster into 0 1 F L by varying of screen at Cross Hatch measurement is made at max 70 F L in Window pattern X 281 20 y 311 20 Y 55 F L The differenc
28. ISTOR CARBON 1 4W 7 5K J R504 24 RESISTOR CARBON 1 4W 8 2K J R326 25 RESISTOR CARBON 1 4W 9 1K J R416 26 RESISTOR CARBON 1 4W 10K J J 138 27 RESISTOR CARBON 1 4W 27K J R421 R502 28 RESISTOR CARBON 1 4W 56K F R113 29 RESISTOR CARBON 1 4W 150K J R454 30 RESISTOR CARBON 1 4W 220K J R316 48 KORTEK Corporation KT 1703NA NO DESCRIPTION SPECIFICATION LOCATION NO 32 RESISTOR CARBON 1 4W 1 8 R452 33 RESISTOR CARBON 1 2W 10 R126 34 RESISTOR CARBON 1 2W 470 508 35 RESISTOR CARBON 1 2W 10K R409 36 CAPACITOR CERAMIC 50V 473pF F Z C115 37 CAPACITOR ELECTRO 25V 10uF KME KMG C313 38 CAPACITOR ELECTRO 50V 0 47uF KME KMG C471 C472 39 CAPACITOR ELECTRO 50V 22uF KME KMG C423 IC401 70 PIN GND 40 CAPACITOR MYLAR 100V 102pF J IC301 14 PIN GND C405 R424 in parallel 41 CAPACITOR MYLAR 100V 472pF J C109 R401 in parallel 42 CAPACITOR P P 250V 155pF 404 43 CAPACITOR P P 630V 103pF C403 44 CAPACITOR P P 1 6KV 752pF J C402 45 HDT KTV 2218A T401 46 COIL LINEARITY 17N 19 5T YELLOW DOT L402 47 MAIN TRANS KTV 4042A 17NA T101 48 DIODE RECTIFIER RG4C 600V 1A D109 49 DIODE ZENER 6 2V 2 3103 IC101 no 2 no 4 50 DY 4PIN 4PIN MOLD YFW800 06 CN401 51 G T PIN DY 6PIN YF
29. Q101 R110 C115 R112 VR101 and R114 in order to supply voltage to the second side stably the voltage provided to IC102 through R111 oscillates the light emission element and generates the potential and feeds back it to IC101 pin4 Then it maintains and controls a stable voltage of the secondary side Also they can control B voltage using Q101 V R101 so controlling desired voltage Pin 13 is a circuit supplying B of vertical output amp and horizontal drive in 26V line and its circuit is composed of D110 and C119 BD104 and C122 Pin 15 supplies B voltage of FBT in 54V line and its circuit is composed of D109 C118 D114 and C121 Pin 16 is output for compensating for voltage according to frequency changes and its circuit is composed of D108 BD101 C124 D118 R118 and Q102 Because with horizontal frequency B of FBT varies with Q102 operation this is a circuit for compensating for this Other circuits of power supply constitute manual degaussing circuit with PH101 18 KORTEK Corporation This is a circuit using temperature characteristics of PH101 and when power is turned on high voltage is applied momentarily and current flows At this time heat is generated and temperature rises With rising temperature as much as resistance increases and after about 20 seconds current stops flowing and this circuit stops operating 6 8 Horizontal Vertical Processor Section
30. R406 Lu wo Lu 5 5 w H SIZE H POSI V SIZE V POSI PINCUSHION CONTRAST 4 ADJUSTMENT 4 1 ADJUSTMENT CONTROL 1 Orientation When servicing always face the monitor to the east 2 Warm up time The monitor must be on for 30 minutes before starting alignment Warm up time is especially critical in color temperature and white balance adjustments 3 Signal Analog 0 714vpp positive at 750 internal termination 4 B line adjustment Signal in adjust in order to 54 0 2V 5 Screen adjust FBT 550 20V 10 KORTEK Corporation 4 2 DISPLAY CONTROL ADJUSTMENTS A SELECT H SIZE FUNCTION ADJUST TO THE HORIZONTAL SIZE IS 350mm 3mm V R404 B SELECT V SIZE FUNCTION ADJUST THE VERTICAL SIZE 15 250 3mm V R304 SELECT H POSI FUNCTION ADJUST CENTER THE PATTERN WITHIN THE RASTER V R305 D SELECT V POSI FUNCTION ADJUST TO CENTER THE PATTERN WITHIN THE RASTER V R501 E SELECT S PCC FUNCTION ADJUST SIDE PINCUSHION ON THE EDGE V R405 F Remove H SYNC to make H SYNC flow and vary V R301 to adjust frequency at 31 5 0 2 Khz G Remove V SYNC to make V SYNC flow and vary V R302 to adjust vertical frequency at 56 0 5Hz Adjust other specific lines at 47 0 5Hz adjust it differently according to the request of buyer H ADJUSTMENT FOCUS1 VR amp FOCUS2 VR ON FBT TO THE OPTIMUM 11 KORTEK Corporation 5 BLOCK DIAGRAM gt gt D D D
31. RBON 1 4W 9 1K F 1177 187 RESISTOR CARBON 1 4W 10K F R332 188 RESISTOR CARBON 1 4W 14K F R327 189 RESISTOR CARBON 1 4W 22K R312 190 RESISTOR CARBON 1 4W 24 5K F R206 191 RESISTOR CARBON 1 4W 56K F R314 192 RESISTOR CARBON 1 4W 68K F R113 193 RESISTOR CARBON 1 4W 82K F R420 194 RESISTOR CARBON 1 4W 100K R325 195 RESISTOR CARBON 1 4W 270K F R316 196 RESISTOR CARBON 1 6W 100 R111 197 RESISTOR CARBON 1 6W 220 R455 198 RESISTOR CARBON 1 6W 330 R210 199 RESISTOR CARBON 1 6W 390 R204 J 104 200 RESISTOR CARBON 1 6W 1K R110 201 RESISTOR CARBON 1 6W 5 6K J R472 202 RESISTOR CARBON 1 6W 820 J R112 203 RESISTOR CARBON 1 6W 10K J R121 204 RESISTOR CARBON 1 6W 68K J R471 205 RESISTOR CARBON 1 6W 15M J R211 206 RESISTOR CARBON 1 6W 2 4K F R114 207 RESISTOR CARBON 1 6W 27K F R421 R502 208 RESISTOR CARBON 1 6W 100K F R333 209 RESISTOR CARBON 1 4W 100 J R513 210 RESISTOR CARBON 1 4W 3 3K J R433 211 RESISTOR CARBON 1 4W 5 1K J R308 212 RESISTOR CARBON 1 4W 10K J R427 213 RESISTOR CARBON 1 4W 12K J R307 R434 214 RESISTOR CARBON 1 4W 30K J R310 215 RESISTOR CARBON 1 4W 75K J R309 42 KORTEK Corporation KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 216 RESISTOR CARBON 1 2W 47 716 217 RESISTOR CARBON
32. RBON 1 6W 1K J R3 25 RESISTOR CARBON 1 6W 3 3K J R1 26 RESISTOR METAL 2W 7 5 R4 27 LEAD WIRE 90mm 28 WAFER LW0640 03 CN2 29 WAFER FA0640 07 CN1 30 JUMPER WIRE 7mm C318 31 RESISTOR CARBON 1 6W 330 R210 47 KORTEK Corporation KT 1703NA UR X Parts list of KT 1703NA UR different from KT 1903NA ST NO DESCRIPTION SPECIFICATION LOCATION NO 1 BEAD CORE ATS3560L 3 5 6mm J124 2 COIL INDUCTOR ALO3 4 7uH LXXX POWER TRANS PIN 80 3 DIODE RECTIFIER EGP20C 150V 2A D111 4 DIODE RECTIFIER 1N4148 75V 150mA 20101 0201 5 DIODE ZENER 10V UZP 108 1W 20301 6 JUMPER WIRE 7 5 mm J 153 J 154 109 162 166 118 IC301 0202 R211 C122e C126 7 JUMPER WIRE 10 mm R4526 C410 163 C119e C122 0305 R321 R320 J UMPER WIRE 12 5 mm J131 J UMPER WIRE 15 mm 8429 J 115 10 RESISTOR CARBON 1 6W 330 R210 11 RESISTOR CARBON 1 6W 680 J R455 12 RESISTOR CARBON 1 6W 2 2K J R114 13 RESISTOR CARBON 1 6W 5 6K J R472 14 RESISTOR CARBON 1 6W 10K J R111 15 RESISTOR CARBON 1 6W 33K R112 16 RESISTOR CARBON 1 4W 15 R104 17 RESISTOR CARBON 1 4W 47 R103 18 RESISTOR CARBON 1 4W 75 R109 19 RESISTOR CARBON 1 4W 470 J R402 20 RESISTOR CARBON 1 4W 1 8K J R401 21 RESISTOR CARBON 1 4W 2K J R505 22 RESISTOR CARBON 1 4W 3 3K F R315 23 RES
33. S and the Contrast Control is output to Pin 19 RED Pin 17 GREEN Pin 13 BLUE and supplied to video output circuit For details see KA2141 Date Book 6 3 VIDEO OUT PUT AMP SECTION VIDEO OUT PUT SECTION AUTO BIAS 6PIN AUTO BIAS B PIN Be we RT R Signal supplied from video PRE AMP is sent to Q903 base The amplitude of Q903 is determined by emitter resistor R938 and collector resistor R937 and R945 Circuit of L903 and C935 are configured for prevention from and compensation of loss of high frequency Video output amp is composed of three circuits of R G and B The above description is about RED circuit For description of GREEN and BLUE circuit see the entire circuit because LOCATION Numbers of the parts are differently applied In A S or when changing values of the parts apply them with full understanding of parts characteristics R938 and R937 are 1 for temperature compensation and R945 is 5 temperature compensation for TR Q903 and for C935 make sure to use a capacitor of NPO type 14 KORTEK Corporation KT XXO3NA 6 4 G2 CONTROL CIRCUIT SECTION G2 CONTROL CIRCUIT 0950 RED 10M AUTO BIAS 2 6PIN GREEN AUTO BIAS 6PIN BLUE AUTO BIAS gt h 6PIN R960 R951 N 15M 102PF 2KV G2 control circuit complements operations of auto bias circuit and when replacing CRT it is not necessary to ad
34. Tek SiH 5 5 5 585 5 i i A 40 8mv Display Style IL Vectors Dots Vector Accumulate 500ms Dot Accumulate 500ms M ious 1 6 SmV Style 1 Readout Graticule Format Options Full ME Tek ACTE 5 5 5 73 5 A 12 2 12 3 smv M tous CAT 7 2 2MV E 9 Feb 2000 10 47 05 35 KORTEK Corporation 8 BILL OF MATERIAL KT 1903NA NO DESCRIPTION SPECIFICATION LOCATION NO 1 JUMP WIRE 7 5mm 950 J 950 J 950 2 JUMP WIRE 8 mm R720 3 JUMP WIRE 8 mm 1919 921 920 911 910 4 JUMP WIRE 7 5 mm 1103 J110 113 114 J118 120 1121 J122 127 J134 135 J136 1139 141 142 145 146 148 J150 J151 152 153 155 156 J160 161 11620 172 174 178 179 190 191 0202 8123 5 JUMP WIRE 7 5 mm 701 6 JUMP WIRE 7 5 mm 930 915 914 922 912 7 JUMP WIRE 7 mm 906 923 926 8 JUMP WIRE 6 mm 1903 904 907 909 901 9 JUMP WIRE 5 mm J 902 10 JUMP WIRE 20 mm 1126 11 JUMP WIRE 15 mm 1101 J119 123 124 125 140 1144 J 147 J 173 12 JUMP WIRE 15 mm 1702 703 13 JUMP WIRE 12 5 mm 1112 J128 132 133 1143 149 169 167 193 14 JUMP WIRE 12 5 mm 908 905 917 15 JUMP WIRE 10 mm 1159 J170 182 194 R104 R328 8331 0301 176 17 JUMP WIRE 10 mm J 708 18 JUMP
35. W500 06 CN402 52 JUMPER WIRE 10mm Above CN203 53 READ WIRE BLACK 150mm 1007 424 J1 114 GND C411 GND 54 READ WIRE BLACK 40mm 1007 424 R507e C405 55 READ WIRE ORANGE 120mm 1007 426 J3 56 READ WIRE RED 120mm 1007 426 J2 57 PCB CEM 1 MAIN 246 196mm 1 6t 58 RESISTOR CARBON 1 6W 3 9K IC301 no 4 PIN GND 59 RESISTOR CARBON 1 6W 6 8K IC201 no 14 PIN GND 60 RESISTOR CARBON 1 6W 10 J 1476 C318 61 RESISTOR CARBON 1 6W 33K R471 62 RESISTOR CARBON 1 4W 1 8M R452 49 KORTEK Corporation KT 1703NA NO DESCRIPTION SPECIFICATION LOCATION NO 63 RESISTOR CARBON 1 4W 15 8332 64 RESISTOR METAL 1W 1 2 R125 65 RESISTOR METAL 2W 2 2 J R123 66 RESISTOR VARIABLE 2KB RVM630H VR401 67 RESISTOR VARIABLE 10KB RVM630H VR403 Q302 68 SCREW TAPPING TP3 8mm 2 CUT 69 TRANSISTOR MCR 100 6 Q301 70 CAPACITOR ELECTRO 400V 220uF 25X40 KME KMG C105 71 RESISTOR VARIABLE 10KB CET065C VR301 72 DIODE 20 1 2W5 1V D901 D902 D903 73 RESISTOR CARBON 1 6W 390 F R901 R902 R903 74 RESISTOR CARBON 1 4W 270K R935 75 RESISTOR CARBON 1 6W 100 F R938 76 F B T KFS 61619 T402 77 SILICONE PAD RUBBER 20 24 0 45t KSD 5072 IC101 78 SCREW TAPPING TP3 8mm 2 CUT 79 SCREW TAPPING TP3 12mm 2 CUT 80 SILICON GREASE YG6111 WHITE 81 JUMPER WIRE 10 mm 82 JUMPER WIRE 12
36. at 33 KORTEK Corporation KT 1903NA 8 IC501 PIN 5 OUT PUT WAVEFORM 7 1C301 PIN 15 OUT PUT WAVEFORM Tek ACTE 10 5 5 7 Acqs Tek 10kS s 34 Acqs si i Cursor a PI 492mv Function 61 2mV Function p V Bars GN ee SCAN SE paired ja m 20 i M sms Chl 2 4 100 M Sms Chl f 2mV Function Time Function Time Unit Unit 1580 Hz Hz 9 1C301PIN8FLY BACK IN PUT WAVEFORM 10DYNAMIC FOCUS WAVEFORM Tek AOA SMS s 73 Acqs A AE Tek SONE 5 5 5 153 Acqs 12 2mv PE O scenes 1 1 12 3mv A 1 7 V Cursor 1 71 V Function Off Bars y Paired 8 so0mv 002 3 dogs ov M ips Chi 7 2209 sz 1 su mg Feb 2000 units 10 47 05 17sec Hz 11 Q402 OUTPUT WAVEFORM 12 Q402 BASE WAVEFORM Tek SONE 5 5 5 23 Acqs Tek 5 5 5 520 Acqs A 936V Cursor 77 2mv Cursor 9 4 Function 77 6mV Function off off v Bars v Bars IE non pem ced Wm 122222 paired e ch zv M 10 5 1 ov M TOns chi Time Time u nits 1 sec Hz 1 sec Hz Units
37. e of X y value should be within MIN 15 MAX 35 7 Other V R Adjustment 1 Measuring condition BS 120 CROSS HATCH PATTERN 31 5 Khz 640X480 MODE 2 Measuring method H SIZE MIN below 320 MAX over 350 V SIZE MIN below 200 MAX over 250 H POS over 20mm from center V POS over 20mm from center 8 HIGH VOLTAGE REGULATION CHECK 1 Measuring terminal CRT ANODE 2 Measuring voltage 23 4 KV 300V 3 Measuring condition To measure the change of screen size at time of max and min in Contrast V R under full white pattern 4 Screen change within 2 0 mm 20 KORTEK Corporation KT 1903NA 7 TROUBLESHOOTING GUIDE 7 1 NO POWER CHANGE FUSE NG CHANGE D101 NG lt 9K CHANGE IC101 NG CHECK amp CHANGE OK O D102 OK lt OK CHANGE 20103 3 CHECK T101 CHECK COMPONENT amp CHANG D116 C102 5G902 903 904 OK KORTEK Corporation 7 2 NO VIDEO CHECK CHANGE D112 KT 1903NA NO VIDEO CHECK R G B NG OK CHANGE SIGNAL CABLE NG 42 OK CHANGE IC901 NG NG OK x lt OK CHANGE Q901 2 3 NG OK CHECK SG501 2 3 CHECK amp COMPONENT CHANG IC902 27 KORTEK Corporation 7 3 NO SYNC PROBLEM KT 1903NA CHECK 6 CHANGE OK C308 R315 OK OK OK END SYNC PROBLEM NG 201 NG 4 CHANGE 0201 NG OK CHECK 6 CHANGE IC301
38. just screen voltage For circuit operations R G B cathode voltage of CRT is detected through R936 R931 and R933 When the voltage is applied to Q904 base Q904 automatically controls screen voltage to maintain screen brightness at a constant level 6 5 AUTO BIAS CIRCUIT SECTION AUTO BIAS CIRCUIT SECTION 2N6517 VVV 47K F 1950 1 2 T 2N6517 E C EN 2N6520 lt Lt S E 5 E Auto bias circuit automatically controls BIAS voltage by detecting the separation between cathode of CRT and grid 1 and compensates for color changes in warm up to maintain them constantly Also when using CRT for a long period the circuit lengthens life of CRT by compensating for deterioration of emission and helps to replace CRT without any other adjustment in A S SUB PCB Pin 4 is connected to cathode of CRT 15 KORTEK Corporation CRT cathode is composed of three electrodes of R and B and GRID 1 electrode is also composed of three electrodes Three electrodes maintain different separations from each other and the voltage proportional to each separation should be supplied to obtain the constant color Because operational principle of circuit is same for R G and B RED circuit will be described instead of describing all circuits When heater voltage is supplied to CRT and surface temperature of the nearest CRT cathode exceeds 900 CRT cathode emits heat electrons At this time
39. lt q MS TLP721 1R4758 1 6W 10K F CAP CAP c lt 250V 258 w 102 122 19NA5 1 6W 2 4K F 6 9 53v CN1 3 FBT LOCKING Power supply is composed of line filter switching amp and switching trans circuit Line filter circuit removes noise element of power line supplied from outside and prevents noise generated in switching amp from flowing out to external power line The circuit is made up of C101 L101 C102 C103 and C104 AC voltage supplied through line filter circuit is supplied to D101 and converted to ripple voltage and converted to DC through the operation of C105 Switching circuit is made up of IC101 peripheral circuits and IC101 performs control and switching operations such as oscillation over voltage protection and overload protection DC rectified through 0102 and lowered passing R102 is supplied to 101 3Pin Vcc then IC101 start operating and outputs pulse NO 3 Pin has over voltage shutdown function embedded in chip if high operates stably at approximately 23 35V voltage or low voltage is input it stops operating temporarily to protect circuit and if high load is applied momentarily embedded overload shutdown function blocks circuit operation and protects circuit to maintain stable operation in outputting pulse 17 KORTEK Corporation 101 pin 1 has OSC function embedded in so that at the first ti
40. me when power switch is turned on embedded OSC oscillates to drive circuits After the initial operation it inputs pulse separated flowing out from FBT in IC101 Pin 5 to match frequencies of monitor and power supply so that it minimizes noise from oscillation and from interference between frequencies of monitor and power supply Also when distance between trans and deflection yoke is near it prevents noise from being generated on screen The switching trans changes and supplies the generated pulse adequately for voltage of each part of monitor and IC101 Pin 4 receives feedback for difference in voltages output to terminal receiving feedback for variations of voltage and increases voltage when it is low and lowers when it is low so supplying the secondary voltage stably T101 secondary side receives the output of the pulse provided to the primary side T101 pin 9 rectifies the voltage at the D116 smoothes it at C116 and outputs 125 V and provides it to the video output terminal R117 and C117 are the circuits to improve the FCC and smoke noises T101 Pin 9 is made up of 125V D116 C116 J175 and R116 circuit Pin 10 and Pin 14 are GNG on the secondary voltage Pin 11 supplies voltage to CRT heater in 6 3V line and its circuit is composed of D111 C123 and R123 Pin 12 supplies operating voltage of video pre amp horizontal amp vertical OSC IC in 12V line and its circuit is composed of D112 C126 and R126 With regard to R111 IC102
41. rols the delay and the width of the waveform for easy operation of auto bias at the pulse oscillator circuit which is composed of IC902 C920 R921 R923 16 KORTEK Corporation KT 1903NA R924 and R922 and outputs it to IC902 Pin 7 Output waveform with not much current is amplified with using OP amp and output to Pin 1 Finally it is supplied to auto bias control circuit 6 7 SMPS CIRCUIT SECTION SMPS CIRCUIT SECTION DEGAUSSING COIL 4 DP38G ie o 149 12 1N4937 1KV 4 7uH CN101 pa LT 1 AC INPUT LINE FILTER K PBS405GU 5 1 A 5 41332 15 7 220v 5490 KME KMH KMG LF2828 2057 1302 560K CN102 2900 2 7 pom 2302 AC 5 LLE T sev V630V 1 14791 473 EGP56G 100 1 184957 100 2200 KME KME 4 KMG Y 15 que KMG qos KMG 1N4937 121 P P TO 1 1000 151 RGP15J AV E 1000 56K 1W KME 7 KME KMG LAS M SSS KMG 1 A gt 39 1N4937 56 390 16 IC1 1 470 250880 3 4 5 8 15 i 472 3 1N4937 100 470 16 KME KMG 1 6W KME KMG R104 KME 77 KMG JUMPER Y 5 6w IK 1 47 50V E K gt 1 KME KMG w228T L 271 NPO 8685 1N4148 4 1 6W 820
42. te the following factory recommended level 4 If the actual level exceeds the max factory set level then immediate service is required to prevent the possibility of premature failure of components 5 To prevent X RADIATION possibility it is essential to use the specified picture tube 6 The nominal high voltage is 24KV and not exceed 27KV at zero beam current at rated voltage KORTEK Corporation 1 2 SERVICING PRECAUTION WARNING 1 First reading safety precaution section of this manual If unforeseen circumstances create conflict between the servicing precautions and safety precaution always follow the safety precautions WARNING 2 A high voltage VR replaced in the wrong direction may cause excessive X RAY Emitting WARNING 3 An electrolytic capacitor installed which the wrong polarity might explode 1 Servicing precautions are printed on the label and should be followed closely 2 Always unplug the AC power cord from the AC power source before attempting to remove or reinstall any component or assembly disconnect PCB plugs or connectors connect all test Components in parallel which an electrolytic capacitor 3 After servicing always check that the screw components and wiring have been correctly reinstalled Make sure that the area around the serviced part has not been demaged 4 Check the insulation between the blades of the AC plug and accessible conductive parts example metal parts input
43. ualified service person s coming 2 Many electrical mechanical parts in this monitor have special safety related characteristics for protection against shock hazard and others These characteristics are often passed unnoticed by a visual inspection and the protection afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage wattage etc Replacement parts which have these special characteristics are identified in the manual and supplements by shading on the schematic diagram and the parts list 3 When replacing Chassis always be certain that all the protective devices are installed properly 4 leakage current check figure 1 KORTEK Corporation READING SHOULD NOT BE ABOVE 0 45mA UNDER TEST AE LEAKAGE CURRENT EXPOSED METAL pa SURFACES ALSO TEST WITH PLUG REVERSED USING AC ADAPTER PLUG AS REQUIRED EARTH GROUND TEST METHODE 1 1 2 X RADIATION WARNING The only potential source of x radiation is the picture tube however when the high voltage Circuitry is operating properly there is no possibility of an x radiation problem The basic precaution is to keep the high voltage at the factory recommended level 1 To measure the high voltage use a high impedance high voltage meter Connect to chassis and to the CRT anode cap 2 Turn the contrast control max clockwise 3 Measure the high voltage The high voltage meter should indica

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