LM721A
Serial Service Manual Rev: A
Page
Page 1111 of
of
of 59
59
17” LCD Monitor
LM721A Srial
Date: Jul-02-03
SERVICE MANUAL
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Page 1: ...Page Page Page Page 1 1 1 1 of of of of 59 59 59 59 17 LCD Monitor LM721A Srial Date Jul 02 03 SERVICE MANUAL All manuals and user guides at all guides com a l l g u i d e s c o m...
Page 2: ...Frequency 30kHz 80kHz V Frequency 55 75Hz Display Colors Over 16 million Colors Dot Clock 135MHz Max Resolution 1280 x 1024 Plug Play VESA DDC2BTM Power Consumption ON Mode 45W OFF Mode 3W Maximum Sc...
Page 3: ...gic brightness control logic and DDC The Inverter board will drive the backlight of panel and the DC DC conversion The Adapter will provide the 12V DC power to inverter power board Inverter Power boar...
Page 4: ...pressed the monitor enters the off mode and the LED turns blank Press again to restore normal status Left Right Button When the OSD show on screen Left Right Button are used to control the monitor fu...
Page 5: ...rce sleeted select Analog or Digital input source 8 Language Multi Language selection 9 Dos mode selected Dos mode resolution selection for 720x400 70Hz and 640x400 70Hz 10 Red Adjusts Red intensity 1...
Page 6: ...IPTION PI N NO DESCRIPTION 1 Red 9 5V 2 Green 10 Detect Cable 3 Blue 11 NC 4 Ground 12 DDC Serial Data 5 Ground 13 H Sync 6 R Ground 14 V Sync 7 G Ground 15 DDC Serial Clock 8 B Ground VGA connector l...
Page 7: ...x768 60Hz 1312x813 48 78 N 60 00 N 64 000 1024x768 70Hz 1328x806 56 476 N 70 069 N 75 000 1024x768 72Hz 1304x798 57 515 P 72 074 P 75 000 1024x768 75Hz 1328x804 60 200 N 74 90 N 80 000 XGA 1024x768 75...
Page 8: ...d Fuse value must no have to change for 115 VAC or 230 VAC operation Leakage Current Less than 3 5 mA Input voltage 240 Volts RMS 50 Hertz Hi Pot Primary to secondary 1 5KVAC for 1 Minute leakage curr...
Page 9: ...lay color 16 2M Colors Number of pixels 1280 x 1024 pixel Pixel Arrangement RGB vertical stripe Pixel pitch 0 264 H x 0 264 W mm Display Mode Normally White 4 4 3 Optical Characteristics The optical c...
Page 10: ...H V open Vopen 1450 1600 1750 Vrms NO LOAD H V Load Vload 710 810 910 Vrms RL 120K Start voltage Vst 1650 1750 1850 Vrms RL CCFL Protect delay time PDT 0 4 1 4 Sec INVERTER MIN BRINGTHNESS Vadj 0 0v L...
Page 11: ...All manuals and user guides at all guides com a l l g u i d e s c o m...
Page 12: ...ge Page Page Page 15 15 15 15 of of of of 59 59 59 59 2 Software Flow Chart 1 2 N Y 5 Y N 10 Y N 12 Y N 7 Y N 6 4 3 8 9 14 11 13 Y N 15 Y N 16 17 19 Y N 18 All manuals and user guides at all guides co...
Page 13: ...and set it to green color Scalar initialize 10 In standby mode 11 Update the life time of back light 12 Check the analog port are there any signals coming 13 Does the scalar send out a interrupt reque...
Page 14: ...Include MCU ADC OSD U203 Flash Memory W39f010P 70B U202 EEPROM 24C16 U204 D Sub Connector CN102 EEPROM 24C02 U104 Hsync Vsync RGB RXD TXD DB15_SDA DB15_SCL EPR_SDA EPR_SCL LVDS THC63LVDM83R U301 U302...
Page 15: ...erter Power Board B uck C onnector P arallet resonant D river D im m ing con trol P arallet resonant inverter C C FL P W M D im m ing control D river C ircuit V in V in inverter P W M C ircuit Inverte...
Page 16: ...LM721A Service Manual Rev A Page Page Page Page 19 19 19 19 of of of of 59 59 59 59 Power Block Diagram All manuals and user guides at all guides com a l l g u i d e s c o m...
Page 17: ...2 3 7 6 5 GND VCC A0 A1 A2 WP SCL SDA R155 0 1 16W R145 100 1 16W A5V VS R117 NC AGND GPIO5 UART_DO FB106 0 C111 NC R122 0 1 16W Connect two grounds at one GND C106 0 01uF R138 120 1 16W RX1 IN R109...
Page 18: ...1 16 2 30 22 A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 DQ7 DQ6 DQ5 DQ4 DQ3 DQ2 DQ1 DQ0 OE WE VCC NC GND A16 NC A17 CE EG1 C250 C252 CHA 5V RMADDR3 OR7 GND RMADDR2 R234 NC FB202 0 EB7 U203...
Page 19: ...TX3 E TX0 E C309 0 1uF 16V C332 0 01uF 16V C331 0 01uF 16V CHANGE EVEN SIGNAL 4 18 GND PPWR P 3 PBIAS P 3 OG0 R307 0 1 16W DHS P 3 DVS P 3 PANEL_P GND OG6 TX0 O C316 0 1uF 16V OG 0 7 P 4 EG1 C329 100u...
Page 20: ...102 150UH C113 470 uF 16V R102 0 C108 0 1 uF 25V R109 1K OP R103 0 OP D101 SR34 OR SMAL340 C103 470 uF 16V U101 SI 8050SD TO263 1 5 4 3 2 VIN ON FBK GND Vout R104 3K OP C101 220 uF 25V TP105 TP_SMD 1...
Page 21: ...2K R222 12K R207 OPEN C207 10U 16V C217 22P 3KV C218 22P 3KV Q212 2SD2098 1 2 3 R231 2K C214 0 18U 100V Q211 2SD2098 1 2 3 R228 2K R229 2K R235 680 R233 1K D206 BAV99 PT202 80AL17T 3 YS 5 9 3 4 6 7 1...
Page 22: ...1 CON204 SM02 8 0 B BHS 1 TB 2 1 R3 120K VR3 15 R8 10 R7 10 R4 120K VR7 15 VR6 15 VR5 15 VR4 15 R10 10 R9 10 R6 120K R5 120K Q1 MMST3904 C0N102 3 8009 12G H 1 2 3 4 5 6 7 8 9 10 11 12 CON101 88A 304...
Page 23: ...Y_AUTO GND BackLight On Off MUTE RP402 10K 1 16W 1 2 3 4 8 7 6 5 C423 150pF KEY ENTER STDBY GPIO7 P 4 C404 150uF 25V GND GND VOL OUT R GND GND KEY_RIGHT C440 150pF GPIO8 P 4 R419 NC CN403 CON403 PITCH...
Page 24: ...Page Page Page Page 27 27 27 27 of of of of 59 59 59 59 Main Board All manuals and user guides at all guides com...
Page 25: ...Page Page Page Page 28 28 28 28 of of of of 59 59 59 59 Inverter Power Board All manuals and user guides at all guides com...
Page 26: ...Page Page Page Page 29 29 29 29 of of of of 57 57 57 57 7 3 Keypad Board and Audio board 1 Keypad Board 2 Audio Board All manuals and user guides at all guides com a l l g u i d e s c o m...
Page 27: ...Maintainability 8 1 Equipments and Tools Requirement 1 Voltmeter 2 Oscilloscope 1 Pattern Generator 2 DDC Tool with a IBM Compatible Computer 3 Alignment Tool 4 LCD Color Analyzer 5 Service Manual 6...
Page 28: ...s Led Green Replace U202 Flash Rom No nothing is show Connected the Signal cable again Check LED status Check Power switch is in Power on status and check if Power switch had been stuck Led Orange OK...
Page 29: ...sured the Q302 pin 5 6 7 8 5 V Check U202 pin 1 2 3 4 5V OK OK Replace Q302 N MOS SI993 Yes Measured the inverter connector CN402 pin 1 on off control 5V on pin2 PWM signal control dim 0V 5V NG Check...
Page 30: ...640x480 60 Hz 31k and LED is Green NG no transition OK Replace GM5120 2120 U203 or replace MAINBOARD Check U203 GM5120 2120 Signal output ER0 7 EG0 7 EB0 7 OR0 7 OG0 7 OB0 7 Is the waveform ok Check U...
Page 31: ...hange F901 check BD901 Q903 IC901 Check the voltage of C905 Check bridge rectified circuit NG OK Check start voltage for the pin3 of IC901 Change IC901 NG Repeating the start voltage Check the auxilia...
Page 32: ...Q201 or Q202 Check the pin1 of U201 have correct wave NG OK Change U201 Check D201 D202 have the output of square wave at short time NG OK Check Q205 Q207 Q203 D201 or Check the resonant wave of pin2...
Page 33: ...57 8 2 3 KeyPad Board OSD is unstable or not working Is KeyPad Board connecting normally Connect KeyPad Board Is Button Switch normally Replace Button Switch Y N N Is KeyPad Board Normally Replace Ke...
Page 34: ...to RGB mode with press MODE button 2 switch the MEM channel to Channel 01 with up or down arrow on chroma 7120 3 The lcd indicator on chroma 7120 will show x 313 10 y 329 10 Y 200 5 cd m2 4 Adjust th...
Page 35: ...20 41 37 30 31 0A 20 20 20 00 20 Note Byte 0C 0D 0E 0F means Serial No Byte 10 11 means Manufacture Time Byte 7F means checksum B DVI Connector Digital x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF...
Page 36: ...EY PAD 1 PCS 1 33L4534 1 LENS POWER 1 PCS 1 34L1061AD7 1B FRONT PANEL 1 PCS 1 34L1062 U0 1B REAR COVER 1 PCS 1 34L1063 U0 B STAND 1 PCS 1 34L1064 U0 B BASE 1 PCS 1 37L 463 1 HINGE 1 PCS 1 40L 152509 R...
Page 37: ...YPE 1 PCS 1 52L6020 1 PROTECT FILM 1 PCS 1 70L L15512AOC DRIVE DISK 1 PCS 1 78L 314 2 4028 SPEAKER 8OHM 1W 1 PCS 1 78L 314 3 4028 8OHM 1W CORE 1 PCS 1 85L 610 1 MAIN SHIELD 1 PCS 1 89L 173 56 8 AUDIO...
Page 38: ...0 16V 1 PCS 2 C922 67L 215102 3H 1000UF 20 16V 1 PCS 2 C921 67L 215102 3K 1000UF 20 16V 0 PCS 2 C922 67L 215102 3K 1000UF 20 16V 0 PCS 2 C906 67L305L101 4 100UF 20 25V 1 PCS 2 C904 67L305S10114H 100UF...
Page 39: ...T A HTL431 1 PCS 3 IC905 56L 158 4 T A HTL431 1 PCS 3 C905 65L 1K152 1T6052 1 5NF 1KV Z5F 10 1 PCS 3 C905 65L 1K152 1T6285 1 5NF 1KV Z5F 10 0 PCS 3 C905 65L 1K152 1T6921 1 5NF 1KV Z5F 10 0 PCS 3 C920...
Page 40: ...5 1 8W 1 PCS 3 R905 61L1207304 CHIPR 300KOHM 5 1 4W 1 PCS 3 R906 61L1207304 CHIPR 300KOHM 5 1 4W 1 PCS 3 R907 61L1207304 CHIPR 300KOHM 5 1 4W 1 PCS 3 R908 61L1207304 CHIPR 300KOHM 5 1 4W 1 PCS 3 R909...
Page 41: ...L 2J47859B WIRE WOUND 0 47 OHM ZW 1 PCS 3 96L 29 6 SHRINK TUBE UL CSA 1 PCS PARENT NO 705L 780 93 03 D 911 ASS Y X 3 90L 396502 D HEAT SINK 1 PCS 3 D911 93L 60226 STPS20H100CT 1 PCS 3 D912 93L 60226 S...
Page 42: ...K OHM 5 1 1 1 PCS 3 R2 61L0805391 CHIPR 390OHM 5 1 8W 1 PCS 3 R8 61L0805391 CHIPR 390OHM 5 1 8W 1 PCS 3 R3 61L0805512 CHIP 5 1KOHM 1 10W 1 PCS 3 R4 61L0805512 CHIP 5 1KOHM 1 10W 1 PCS 3 C14 65L0805101...
Page 43: ...26 gm2120 CG 1 PCS 3 Q302 56L 566 1 SI9933ADY T1 0 PCS 3 Q302 56L 566 6 SI9953DY T1 1 PCS 3 U201 56L 643 2 TCM809S ENB713 1 PCS 3 U204 56L1133 33 M24C16 MN6T 1 PCS 3 U104 56L1133 34 M24C02 WMN6T SMT 1...
Page 44: ...PCS 3 R207 61L0603103 CHIPR 10K OHM 5 1 16 1 PCS 3 R208 61L0603103 CHIPR 10K OHM 5 1 16 1 PCS 3 R214 61L0603103 CHIPR 10K OHM 5 1 16 1 PCS 3 R215 61L0603103 CHIPR 10K OHM 5 1 16 1 PCS 3 R221 61L06031...
Page 45: ...OHM 5 1 16W 1 PCS 3 R133 61L0603750 CHIPR 75 OHM 5 1 16W 1 PCS 3 R134 61L0603750 CHIPR 75 OHM 5 1 16W 1 PCS 3 R135 61L0603750 CHIPR 75 OHM 5 1 16W 1 PCS 3 R240 61L0603750 CHIPR 75 OHM 5 1 16W 1 PCS 3...
Page 46: ...217 65L0603104 12 0 1UF 10 16V X7R 1 PCS 3 C218 65L0603104 12 0 1UF 10 16V X7R 1 PCS 3 C219 65L0603104 12 0 1UF 10 16V X7R 1 PCS 3 C220 65L0603104 12 0 1UF 10 16V X7R 1 PCS 3 C223 65L0603104 12 0 1UF...
Page 47: ...P 150PF 50V X7R 1 PCS 3 C423 65L0603151 32 CHIP 150PF 50V X7R 1 PCS 3 C439 65L0603151 32 CHIP 150PF 50V X7R 1 PCS 3 C440 65L0603151 32 CHIP 150PF 50V X7R 1 PCS 3 C253 65L0603220 31 CHIP 22PF 50V NPO 1...
Page 48: ...RP201 71L 56A121 8T CHIP BEAD ARRAY 120 OHM 1 PCS 3 FB210 71L 56U600 CHIP BEAD 60 OHM 1 PCS 3 FB401 71L 56U600 CHIP BEAD 60 OHM 1 PCS 3 FB402 71L 56U600 CHIP BEAD 60 OHM 1 PCS 3 FB403 71L 56U600 CHIP...
Page 49: ...AT MKT CAP 0 18UF 5 100 1 PCS 2 C214 64L179J1841AT MKT CAP 0 18UF 5 100 1 PCS 2 C215 65L 3J2206EM 22PF 5 3KV MURATA 0 PCS 2 C216 65L 3J2206EM 22PF 5 3KV MURATA 0 PCS 2 C217 65L 3J2206EM 22PF 5 3KV MUR...
Page 50: ...201 33L8020 4 J WAFER 4P BH BY JST SMT 0 PCS 3 CON202 33L8020 4 J WAFER 4P BH BY JST SMT 0 PCS 3 U101 56L 563 1 LM2596S 5 0 SMT 0 PCS 3 U102 56L 563 7 AIC1084 33CM 1 PCS 3 U103 56L 563 9 AIC1084CM 1 P...
Page 51: ...R 15KOHM 5 1 16W 1 PCS 3 R211 61L0603153 CHIPR 15KOHM 5 1 16W 1 PCS 3 R220 61L0603153 CHIPR 15KOHM 5 1 16W 1 PCS 3 R221 61L0603153 CHIPR 15KOHM 5 1 16W 1 PCS 3 R222 61L0603153 CHIPR 15KOHM 5 1 16W 1 P...
Page 52: ...0 1UF 10 25V X7R 080 1 PCS 3 C202 65L0805104 22 0 1UF 10 25V X7R 080 1 PCS 3 C204 65L0805104 22 0 1UF 10 25V X7R 080 1 PCS 3 C205 65L0805104 22 0 1UF 10 25V X7R 080 1 PCS 3 C206 65L0805104 22 0 1UF 10...
Page 53: ...1 PCS 3 D201 93L2004 1 SMAL240LVXRO SMT 0 PCS 3 D202 93L2004 1 SMAL240LVXRO SMT 0 PCS 3 D201 93L2004 2 SR24 PANJIT SMT 1 PCS 3 D202 93L2004 2 SR24 PANJIT SMT 1 PCS 3 D101 93L3004 1 SMAL340XXXRO 3A 40V...
Page 54: ...1GHJ KEY SWITCH 1 PCS 2 DP101 81L 12 1 GP LED 1 PCS 3 715L 982 1 S KEY BOARD 1 PCS 3 J001 95L 90 23 TIN COATED 1 PCS 3 J002 95L 90 23 TIN COATED 1 PCS 3 J003 95L 90 23 TIN COATED 1 PCS 3 J004 95L 90 2...
