920C - 720C COLOR MONITOR SERVICE Manual CONTENTS 1. Precautions 2. Product Specifications 3. Disassembly & Reassembly 4. Alignment & Adjustments 5. Troubleshooting 6. Exploded View & Parts List 7. Electrical Parts List 8. Block Diagram 9. Wiring Diagram 10. Schematic Diagrams Note: Sections 6, 8, 9 and 10 are in hardcopy format in the printed supplement.
Components identified by on schematics and parts leads are not pinched or that hardware is not lists must be sealed by a soldering iron after lodged between the chassis and other metal parts in replacement and adjustment. the monitor. 720C/920C...
Òanti-staticÓ a carpeted floor can generate enough static can generate electrical charges sufficient to damage electricity to damage an ESD. ESDs. Indicates ESDs on the Schematic Diagram in this manual. 720C/920C...
Humidity : 10 % to 80 % Storage Temperature -4°F to 113°F (-20°C to 45°C) Humidity : 5 % to 95 % • 920C/720C complies with TCO 99 recommendations for reduced electromagnetic fields. • Designs and specifications are subject to change without prior notice. 720C/920C...
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B : Horizontal sync width O : Frame time total P : Vertical sync width C : Back porch D : Active time Q : Back porch R : Active time E : Front porch S : Front porch 720C/920C...
3 Disassembly and Reassembly This section of the service manual describes the disassembly and reassembly procedures for the Nokia 920C/720C (19" ~ 17") monitors. WARNING: This monitor contains electrostatically sensitive devices. Use caution when handling these components. 3-1 Disassembly Cautions:1. Disconnect the monitor from the power source before disassembly.
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4 plastic ties on the Bracket. 3. Disconnect CN201, CN409, CN601, H_DY, 2. Lift the Degaussing Coil Assembly from the CN604 and Anode Cap on the Main PCB Bracket. Assembly. 3-2 Reassembly Reassembly procedures are in the reverse order of Disassembly procedures. 720C/920C...
Warm-up time is especially 720C TOSHIBA critical in color temperature and white balance adjustments. 525V 635V 4-1-1 (d) SIGNAL 920C Analog, 0.7 Vp-p positive at 75 ohm, internal termination Sync: Separate/Composite 560V 530V (TTL level negative/positive) Sync-on-Green: Composite sync 0.3 Vp-p negative (Video 0.7 Vp-p positive)
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If the monitor again fails to Connect the monitor to the signal generator and/ meet specifications in every direction, contact or PC as illustrated in Figures 4-1 and 4-2. your Regional After Service Center for possible CRT replacement. 720C/920C...
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Maximum Adjust the horizontal size and vertical size to their optimal settings: 355 mm (H) x 266 mm (V)/920C. Click on the << or >> box next to V_POSI to 310 mm x 232 mm/720C. 1280 x 1024 mode (91kHz/85Hz) center the vertical image on the raster.
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Display image: Crosshatch pattern Brightness: Cut-off 4-2-10 Save the Data Contrast: Maximum To save the adjustment data for a mode, press Click on the << or >> box next to PARALLEL to FACTORY SAVE. make the image area rectangular. 720C/920C...
Measurement instrument: Color analyzer Display image: Green box pattern Scanning frequency: 68 kHz/85 Hz Brightness: Cut-off 355 (H) x 266 (V)/920C ~ 310 X 232/720C Display Size : Contrast: Maximum Display image: White flat field at center of display area 1.
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B_GAIN to make the video white. to the procedure on page 4-5. (For 5000K color adjustment: x = 0.346 ± 0.02, y = 0.359 ± 0.02.) 2. Refer to the procedure for 9300K, section 4-3-2 (c) steps 2 and 3. 720C/920C...
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For trained and experienced service technicians (1024 x 768) only. Display image: White flat field Use the following procedure to correct minor 355(H) x 266(V)/920C ~ 310(H) X 232(V)/720C Display size: color purity problems: Brightness: Cut off point Contrast: Maximum 1.
CH1 P-P = 544 V CH1 RMS = 332.4 V Check and replace IC601, IC601 Pin 1 waveform is right? IC602, IC604. IC602 and IC604 Replace parts and verify voltages. are right? Normal operation Replace Main board. Verify voltages. Done. 720C/920C...
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H/V sync video level. Make no H/V sync (power off mode) LED blinks Check IC201 Pin 39. +12 V line off Check IC201 Pin 9. Check IC201 Pin 10. Q632 Base driving voltage exists? Check and replace Q632. Done 720C/920C...
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CH1 P-P = 55.2 V CH1 RMS = 9.52 V Q261 and Q262. 12.08 V (IC261, #26) 1.216 kV (Q405, Collector) CH1 P-P = 12.08 V CH1 RMS = 7.396 V CH1 P-P = 1.216 kV CH1 RMS = 316 V 720C/920C...
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Check some parts around IC403. Check L403. 5-1-6 Invariable H_Size IC261 Pin 28 voltage varies with Check and replace IC261. different H_Size DAC values? IC401 Pin 6 output duty varies with Check some parts around IC261 Pin different H_Size DAC values? 28, IC401. 720C/920C...
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IC261 Pin 24 output exists? Check and replace IC261. Check and replace IC402. Check some parts IC402 Pin 2 and IC261 Pin 24. 5-1-9 Para. or Pin Balance Failure IC261 Pin 24 output varies with different DAC values? Replace IC261. 720C/920C...
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Refer to 5-1-1 No Power Supply IC261 Pin 23 output exists? Check and replace IC261. IC301 Pin 1 input exists? Check R276 and R304. Check and replace some parts IC301 Pin 6 output exists? around IC301. Check V DY connector connection. 720C/920C...
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Check some parts around IC301. different DAC values? Check bias voltage. Check and replace IC261 and IC301. 5-1-13 High Voltage Failure Check +12 V line. Q524 gate driving pulse exist? Check and replace Q521, Q522, Q523, Q524 and IC501. Done 720C/920C...
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CH1 P-P = 2.20 V CH1 RMS = 2.776 V 580 V (T551, #1) Some parts around T502 are right? Replace failed part. CH1 P-P = 580 V CH1 RMS = 278.2 V Check the connection between FBT Pin 13, CRT Socket PCB. 720C/920C...
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Pin 1, 3, 5) outputs are right? Check and replace IC102 (17”: IC105). Check +80 V line. Cathode DC levels are right? Check and replace IC101 and IC104 (17”: IC104). Check G2 wire, CRT Socket board, G2 voltage is right? and FBT. Change CRT. Done. 720C/920C...
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CH1 P-P = 3.42 V CH1 RMS = 2.500 V 3.16 V (IC201, #32) IC201 Pin 18 input is right? Check IC202. CH1 P-P = 3.16 V CH1 RMS = 2.560 V All in/output values are right? Replace IC201. Done 720C/920C 5-10...
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Check and replace IC103 (17”: IC04) . 22 outputs are right? (17” only) IC101 (17”: IC104) Pins 4, 9 and 13 Check and replace QB51, inputs are right? QG51 and QR51. Check and replace IC101 (17”: IC104) . Done 720C/920C 5-11...
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RL601 operation is right? Check D-Coil, TH601. Q630 base input is right? Check and replace Q630. Check and replace IC201. IC201 Pin 40 output is right? Check user function key. R217 and R630 are right? Replace R217 and R630. Done 720C/920C 5-12...
5-2-2 Shut Down Blinking LED’s? Check power supply. Check horizontal, vertical deflection Scan failure system and check power supply secondary voltages. High voltage failure? Check high voltage system. Video failure? Check Video board. Check and replace IC201. Done 720C/920C 5-13...
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Are proper DC voltage on all and 21) Pins 10, 11 and 12. cathodes? Check QB02, QB03, QG02, QG03 QR02 and QR03. Check G2 wire, G2 control, volume Is G2 voltage right? and FBT. Change the CRT. Done 720C/920C 5-14...
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Check Q301. Pin 17 of IC103 (17”: IC04)? Check Pins 24, 25 and 26 of IC101 (17”: 19, 20, 21 of IC104) . Is blank pedestal on all cathodes? Check QB02, QB03, QG02, QG03, QR02 and QR03. Done 720C/920C 5-15...
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Signals at Pins 1, 3 and 5 of IC1 Replace IC1. are right? Signals at CN201 Pins 6, 9 and Check wire dressing and connections. CN102 Pin 6 are right? Check circuits on Main board. (IC201 and IC261) Done 720C/920C 5-16...
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5 Troubleshooting 5-2-6 Misconvergence Try readjusting convergence. Is the convergence now Done within spec? Readjust convergence. Is the convergence now Done within spec? Change CRT and readjust convergence. Done 720C/920C 5-17...
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Refer to 5-1-15 Dynamic Is dynamic focus circuit right? Focus Failure. Replace the CRT and verify focus. 5-2-8 Purity Failure Degaussing Purity is right? Done Degaussing circuit is right? Refer to 5-1-20 Degaussing Failure. Replace CRT and verify purity. 720C/920C 5-18...
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10-7 Connector and Option Boards Parts Schematic Diagram CN142 slcon4p CN141 slcon4p CN208 720C/920C 10-7...
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It has been agreed between Nokia and Samsung to comply with the After Sales concept described below. 1. Invoicing: Samsung Euro C.S. Head Office will receive Nokia TPMs Invoice – at Nokia rate specifically agreed for this product – direct from Nokia TPM.