Service Manual ViewSonic A90f+-1 Model No. VCDTS23307-2R 19” Digital Controlled Color Monitor (A90f+-1_SM_602-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.
A reading of less than 3.5mA should obtained (ref. EN60950). Equipment Under test Isolating transformer Equipment safety Earth terminal Measuring instrument Fig. 1 Measurement of AC Leakage Current ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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SR801 CSA-SS-212DM5 RELAY 5054613402 F801 250V/3.15A FUSE 5054431539 T801 TPW-697 POWER TRANSFORMER 5061369700 T101 (RA) TFB-280T TRAQNS.FLYBACK COLOR 5062628031 T101 (RB) TFB-280L TRAQNS.FLYBACK COLOR 5062628032 V901 (RA) M46QCK761X123 (TCO CCRT/DY 5051286346 MDT) ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
–40 C to +60 C Environmental Conditions Operating Humidity 10% to 90% Storage Humidity 10% to 95 % Dimensions W x H x D 575 mm x 600mm x 630mm Weight 25.5Kg (Gross) ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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16.667 0.613 0.04 VESA 1280 X 1024 79.976 12.504 9.481 1.837 1.067 13.329 12.804 0.475 0.038 75Hz 75.025 VESA 1024 X 768 48.363 20.677 15.754 2.462 2.092 16.666 15.880 0.600 0.124 60.004 ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
3. Control Location and Functions Front view UltraBrite Mode Power switc Power switch UltraBrite Mode “1” key Led indicator Auto Sizing Down “2” key Rear view 15 pin D Sub AC input ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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“ Icon. Fig. 0 Factory OSD Menu 4.2 User OSD menu descriptions Press “1” key to display a basic main menu (1) shown as below. FIGURE 1( USER MODE OSD MENU 1) ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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The three default color modes (9300k, 6500k, 5000k) are factory preset, User can select these default colors but can’t adjust and save. If “USER COLOR” is selected, then pressing “2” key will display next sub menu as below to start color adjustment. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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In main menu(2), if “LANGUAGE” is selected, then pressing “2” key will display next sub menu as below for languages selection If “view meter” is selected, then pressing “2” key will display next sub menu as below to display timing information. (VIEWMETER) Normal brightness / High brightness ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
Degaussing coil cover. (Fig 4-4) connector and the CRT grounding connector from the FBT shield. 4. Disassembly Instructions (Fig 4-1) (Fig 4-2) (Fig 4-4) (Fig 4-3) ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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4.CRT Removal a) CRT is supplied as ITC. b) Remove 4 screws (F) from the front cover (Fig4-7) to move the CRT CAUTION: Do not lift the CRT by the neck. (Fig 4-7) ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
5-1.The Pin-assignments of the 15pin D-sub male miniature connector are shown below: 15 Pin Min D-sub male connector PIN NO PIN DESCRIPTION GREEN BLUE NO CONNECTION GROUND R-GROUND G-GROUND B-GROUND +5V PC97 GROUND NO CONNECTION SDA FOR DDC H.SYNC. V.SYNC. SCL FOR DDC ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
( ).To connect Power Cord between your monitor and wall outlet, you have to connect the power cord to the monitor power input socket on back of the monitor. Plug the other end of the power cord into your surge protector or properly-grounded electrical outlet. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
When output voltages are too high, voltage across C817 will be high and voltage drop on R872 is also high. It will force Q808, Q807 to conduct and pin8 of UC3842 to ground. Thus UC3842 stop to operate. ViewSonic Corporation A90f+-1...
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I901 and I903 will operate normally. Pin 17 ~ pin 20 provide the logic to control the horizontal CS linear correction circuit according to the horizontal frequency range as the following table. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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The controlled currents are independent of Horizontal. Freq. The PLL 2 thus compensates for the delay in the output horizontal deflection CKT by adjusting the phase of the HDRV (pin26) output pulse. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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I301 will linearly increase with a charge time of determining by R326 and C308 to modulate B+ duty. Horizontal DC centering circuit is build by Q423, Q424. By controlling the small current flow in or out of L405, it will provide DC center compensation for CDT. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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Grid 1 of CDT. When monitor turns off, pin3 (H.UNLOCK) is pull high to turn off Q108 via D108. Grid 1 of CDT is then pulled down to most negative voltage from pin7 of FBT to protect CDT. ViewSonic Corporation A90f+-1...
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Q933, Q963 individually. The DC bias of the cathode is then varied to optimize the color temperature of background. Brightness control: Pin 2 of IA01 provides Brightness control. It feed through P903 to base of Q910 to vary R, G, and B bias at cathodes simultaneously. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
Increase adjust value or clock wise select Icon 7-1 B+ ( 82V) output voltage adjustment a). Apply Chroma 2225 signals with any pattern to the monitor. b). Connect AC input and power on the monitor. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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Turn on the monitor by pressing power switch and OSD on/off key at the same time, release power switch and continue to press enter key, then release the enter key after display appears. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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1). Pattern: CHROMA 2250, Pattern 1. Brightness: Center. Contrast: Max. 264 2mm 2-a). Select ”Vertical Height” Icon. (Every Mode). -b).Pressing ”UP or DOWN” Key and (Every Mode.). Adjust ”Video display” to 264 +/- 1 mm. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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2). Pressing “ UP or DOWN” Key and adjust (Every Mode) to get the best. d).Keystone Adjustment 2-d). Keystone Adjusts: 1). Select “Keystone” Icon. 2). Pressing “UP or DOWN” Key and (Every Mode) adjust to get the best. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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” Adjustment. , Pin-corner Icon. (Every Mode). b). Press “UP or DOWN” Key to adjust. (9). Brightness. Brightness set at Center. . Brightness: Center. (10). Contrast. Contrast set at Max. Contrast: Max. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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*Brightness: 95; Contrast: max. *Select ”Color” Icon. Select 5000 K /Su50: 1).R,G,B bias : set at 107 ( Samsung ), 2).adjust “ R,B “ bias to: x =0.310 0.004, y =0.310 0.004. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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6500K, and 50 +/- 0.3 FL for * Test point: CRT center. Sup65(high brightness), then adjust “ R,B” Gain to x=0.313 0.01, y =0.329 0.01; Y (6500K): 41 +/- 1FL Y (Sup65): 70 +/- 1 F/L. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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*Mode 13: 1280 x 1024, 75 HZ. *Brightness: center 1. Color: 9300 K, only. (9300 K. Only) Contrast: max. 2. Pattern: 27.5~29. FL (Full *Pattern: Pattern 41 (Full White). White). Adjust ABL VR(R167) to 29 0.5 F/L. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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(15). Language set up. Set “English “as default. (16).Zoom setting. Press recall to set at center. (17) Key setting. preset mode (set finish) set at : a). “HR” Icon: off. b). “KEY” mark: on. ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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Connectors P901, P902 Check pin 23,21of IA01 Check if XA01 Check B+(5V) Pin23= High, pin21= Low waveform exist ? to IA01 exist ? Replace MCU (IA01) ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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Check SMPS DC O/P Check G2 (P906) build by Q114, 115, 116 (SECTION 1) connection Is the voltage 6.3V at heater? Check CRT R, G, B cathode and G1 Check P904, P903 connection ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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T101(FBT) Screen VR to extreme ) Check I C bus from Pin27,28 I301 Pin3 of IA01 to HUNLOCK HIGH ? IA02,I301,I901 P401CONNECTION proper ? Check IA01 and its peripheral CKT Replace IA01 ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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Drain of Q402 Proper ? Is output of Q400,Q421 proper ? Is Q404 output proper ? Is output at Pin 28 Is output at Pin 26 of I301 proper? of I301 proper ? REPLACE I301 ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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Pin 2 of I310 = 15 V approx. Pin4 of I310 = -15 V approx Check S.M.P.S. DC output. I310 Pin1,Pin7 Input proper ? Are there output at pin 3,5 of I301 ? Check I301 AND Peripheral CKT ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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Check I C Bus (P903A to P904). Press Enter key, there should be a sequential pulse appear for I C communication I903 Vdd = 5V ? Check I903 and its peripheral circuit ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
9. Recommended Spare Parts List LEAD TIME LOCATION VIEWSONIC P/N PART NO. DESCRIPTION PCB ASSEMBLY: 3 WEEKS U0334 Main Board. PWB-0334B. 3 WEEKS U0414 B-CRT-0217-0093 5053104140 Video Board. PWB-0414. 3 WEEKS U0488 5053104880 Control Board. PWB-0488. CABINETS: 3 WEEKS 6V04...
Before replacing any of these components, read carefully the product safety precautions. Do not degrade the safety of the display through improper servicing ABBREVIATIONS: 10.ELECTRICAL PARTS LIST LOCATION VIEWSONIC P/N PART NO. DESCRIPTION CAPACITOR: E-C-0404-4749...
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C.CE 2KV 330PF K E-C-0404-4756 C413 5214222991 C.EL 160V 2.2UF M E-C-0404-4363 C414 5206422991 C.EL 250V 2.2UF M E-C-0404-4365 C415 5214019512 C.EL 25V 1000UF M E-C-0404-4387 C416 5270207401 C.ME 400V 0.22UF J ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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C.EL 16V 1000UF M E-C-0404-4748 C881A 5234318191 C.CE 2KV 180PF K E-C-0404-1171 C882A 5234327191 C.CE 2KV 270PF K E-C-0404-4750 C883 5234333101 C.CE 2KV 330PF K E-C-0404-3352 C886 5276110491 C.ME 100V 0.1UF J ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
A90f+ (F19FSVZ) Control Control Regulator BLOCK DIAGRAM ACV Input Regulator Rectifier Filter 100/240VAC +193V Protection +82V Switching +15V To Time base & Video CKT Transistor Controller -15V Frequency Feedback ON/OFF reduction Control Control ViewSonic Corporation A90f+-1 Confidential – Do Not Copy...
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