Service Manual ViewSonic VG500b-1 Model No. VLCDS24349-1 15” Digital Controlled Color Monitor (VG500b-1_SM_574-Rev. 1.0-October 2002) ViewSonic 381 Brea Canyon Road, Walnut, California 91789 USA - (800) 888-8583...
Further, ViewSonic reserves the right to revise this publication and to make changes from time to time in the contents hereof without obligation of ViewSonic to notify any person of such revision or changes.
2. Keep wires away from high voltage, high temperature components and sharp edges. 3. Keep wires in their original position so as to reduce interference. 4. Adjustment of this product please refer to the user’ manual. ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
SERVICE TOOLS & EQUIPMENT REQUIRED 1. SIGNAL GENERATOR: Chroma 2237 or equivalent 2. MULTIMETER Fluke 45 or equivalent 3. SCREW DRIVER 4. OSCILLOSCOPE Tektronik TDS3054 digital oscilloscope or equivalent 5. SOLDER IRON ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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Pin No. Symbol Signal Description 0.7vp-p (VIDEO) GREEN 0.7vp-p (VIDEO) BLUE 0.7vp-p (VIDEO) GROUND GROUND GROUND GROUND GROUND VCC_+5V PC +5V GROUND N.C. DDC_SDA DDC1/2B DDC_SCL DDC1/2B VGA_VSYNC VSYNC TTL positive or negative ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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3.4 Main DC+12V Input (J800 on I/F Board) Pin No. Symbol Function Ground DC+12V Main DC+12V Input Ground 3.5 Audio Input Jack (J701 on I/F Board) Pin No. Symbol Function Ground L_CH_Audio Input R_CH_Audio Input L_CH_Audio Return R_CH_Audio Return ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
Blue data signal of odd pixel Blue data signal of odd pixel Blue data signal of odd pixel Blue data signal of odd pixel Blue data signal of odd pixel Blue data signal of odd pixel Ground ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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DC-6V for frame dark VDDG DC+18V for frame white VDDG DC+18V for frame white CLKV Sampling Clock for frame line STV1 Trigger the first line per frame VDDD DC_3.3V for panel VCC ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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Audio standby control (High standby, Low normal) DC+5V DC+5V DC+5V DC+5V Ground MUTE+ Audio mute control (Voltage High speaker off, Low speaker on) Brightness adjustment (Low is max., High is Min.) CCFL_EN Backlight lamps enable (ON/high, OFF/low) ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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Brightness adjustment (Low is Max., High is Min.) DC+5V DC+5V CCFL_EN Backlight lamps enable (ON/high, OFF/low) CN701 (S5BPH-K): Connect to control board, control the audio Pin No. Symbol Function L_CH_SP_-Signal L_CH_SP_+Signal GND_S1 Ground R_CH_SP_-Signal R_CH_SP_+Signal ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
Scalar(U400) Hangs Still no sync are not Picture absent The Voltage across Replace F802 D802 is 5V Check U300 ReplaceU401 Replace U300 Still no Picture Check U301 ReplaceU400 Replace U301 (gm2115) Replace U401 ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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Replace U220 The Voltage of U220 #2 is 3.3V ReplaceD220 The Voltage after D220 is 2.5V Replace U401 Still No LED Check X400 crystal Replace X400, C447, clock C448 Replace U400 (gm2115) ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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LCD panel H, V, DE) CN502 connectors CN501, CN502 normal Tighten two flex Are the input Replace V901 (LCD cables at CN501, waveforms of panel) CN502 gm2115 normal ReplaceU400 ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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Check if CN701 is connected to CN101 properly Check U801 output U701 #1 voltage is Replace U801 #7 is normal 10.5V U803 #8 is 10.5V Check U701 output #2,#4,#10,#12 are normal Replace U803 Replace U701 ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
Switch pattern to full screen “pixel on/off” pattern with R, B color off and Green on. Green color level set at level 255. Adjust VR601 until whole screen display stable and flicker free. ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
When mute is activated, the Q703 will be forced to saturation to block sound output. When standby is activated, the Q705/Q704 will also go to saturation to bypass the sound input signal to ground. The sound outputs of U701 will drive speakers via CN701 connecter. ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
4A/125V 510mA D220 410mA VOUT STDBY US1G VOLUME C220 C221 C224 R220 C225 T-B12B-ZR 470uF/10V 0.1uF 220uF/16V 510R 220uF/16V Title 2.0 Keyboard Size Document Number E91001 Date: Wednesday, October 02, 2002 Sheet ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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DDC_SCL R315 100R DDC_SDA R316 100R SCL_1Y0 C302 C316 SCL_1Z 100pF 100pF U301 GPIO7/SW R301 74HC4052D SDA_2Z SDA_2Y0 Title 3.0 Analog Input Size Document Number E91001 Date: Wednesday, October 02, 2002 Sheet ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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R417 H-PROTO SCLPOL R418 RM-A5 gm2115 S4BPH_J TS-PQFP208 RM-A0 R415 MUTE+ Default is adding R421,R426,R427.Others keep open. ADC_GNDT Title 4.0 gm2115 Size Document Number Custom E91001 Date: Wednesday, October 02, 2002 Sheet ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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CLKH- CLKH- HMS1_O IL-FHR-50S-HF IL-FHR-50S-HF HMS1_O HMS2_E HMS2_E DHS_LP DHS_LP EPOL EPOL STH1 STH1 CLKV CLKV STV1 Title STV1 5.0 Panel Interface Size Document Number E91001 Date: Wednesday, October 02, 2002 Sheet ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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C625 C626 2.2K R623 10uF/16V 10uF/16V 0.1uF R633 1.25K PPWR0 Q606 18R 1% DTC114TKA/KSR1110 VR601 1K 0.1W Title 6.0 Panel Volt Size Document Number Custom E91001 Date: Wednesday, October 02, 2002 Sheet ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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DTC114TKA/KSR1110 Volume volume R833 C831 T-B12B_ZR 2.2K 0.1uF Lo Lightest Q831 C834 DTC114TKA/KSR1110 HI OFF 33uF/10V LO ON Title 7.0 POWER Size Document Number E91001 Date: Thursday, May 30, 2002 Sheet ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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R704 Volume GND_S1 GND_S1 C707 4.7K Q703 DTC114TKA/KSR1110 330uF/6.3V MUTE+ MUTE+ DTC114TKA/KSR1110 C714 GND_S1 0.1uF GND_S1 GND_S1 GND_S1 Title 7.1 SOUND AMP Size Document Number E91001 Date: Thursday, May 30, 2002 Sheet ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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S108 S107 S106 S105 S104 S103 S102 S101 CSL-F300YG2CT SKHHPL2420-TT SKHHPL2420-TT SKHHPL2420-TT SKHHPL2420-TT SKHHPL2420-TT SKHHPL2420-TT SKHHPL2420-TT SKHHPL2420-TT Title VIEWSONIC KEY PAD BOARD Size Document Number E91001 Date: Tuesday, May 07, 2002 Sheet ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...
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PWB-0420 TIV-092B Inverter ViewSonic Corporation VG500b-1 Confidential – Do Not Copy...