CONFIDENTIAL 1 Precautio 1-1 Safety Precautions WARNINGS Inspect all protective devices such as nonmetallic For continued safety, do not attempt to modify the control knobs, insulating materials, cabinet backs, circuit board. adjustment and compartment covers or shields, isolation resistor-capacitor networks, mechanical Disconnect the AC power before servicing.
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CONFIDENTIAL 1 Precautions 1-2 Servicing Precautions WARNING1: First read the “Safety Precautions” section of this manual. If unforeseen circumstances create conflict between the servicing precautions and safety precautions, always follow the safety precautions. WARNING2: A high voltage VR replaced in the wrong direction may cause excessive X-ray emissions.
CONFIDENTIAL 3 Disassembly and Reassembly This section of the service manual describes the disassembly and reassembly procedures for the CF21G* monitor. WARNING: This monitor contains electrostatically sensitive devices. Use with caution when handling these components. 3-1 Disassembly Cautions:1. Disconnect the monitor from the power source before disassembly. 2.
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CONFIDENTIAL 3 Disassembly and Reassembly 3-1-7 Removing the Video PCB Assembly 3-1-9 Removing the Main PCB Rear Shield and Video PCB 1. Remove 6 screws on the main PCB. 1. Remove the 3 screws on the PCB Assembly. 2. Pull the Main PCB towards you and carefully 2.
Composite sync 0.3 Vp-p negative ET-4000 chipset (strongly recommended if (Video 0.7 Vp-p positive) using Samsung DM 200 software) and that displays: 1280 x 1024 @ 85 Hz, or 1600 x 1200 4-1-1 (d) SCANNING FREQUENCY @ 85 Hz (maximum).
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CONFIDENTIAL 4 Alignment and Adjustments 4-2 Display Control Adjustments 4-2-1 Centering 4-2-1 (d) VERTICAL POSITION ADJUSTMENT Centering means to position the center point of CONDITIONS the display in the middle of the display area. Scanning frequency: 91 kHz / 85 Hz Horizontal size and position and vertical size and Display image: Crosshatch pattern...
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CONFIDENTIAL 4 Alignment and Adjustments 4-2-2 (b) VERTICAL LINEARITY ADJUSTMENT CONDITIONS Scanning frequency: 91 kHz / 85 Hz Display image: Crosshatch pattern Brightness: Cut-off Contrast: Maximum 4 mm To adjust the Vertical Linearity, refer to Table 4-1 Figure 4-6. Parallelogram for the tolerance range.
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CONFIDENTIAL 4 Alignment and Adjustments 4-3 Color Adjustments 4-3-1 Color Coordinates (Temperature) 4-3-2 (b) G-GAIN ADJUSTMENT Color temperature is a measurement of the 1/3H-1/2H radiant energy transmitted by a color. For computer monitors, the color temperature refers FRONT BEZEL OPENING to the radiant energy transmitted by white.
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CONFIDENTIAL 4 Alignment and Adjustments Luminance Table (9300K) 4-3 4-3-3 (b) G-GAIN ADJUSTMENT This procedure is the same as that for 9300K, refer 21” to the procedure on page 4-5. Without ABL 32 ft-L Adjust the brightness of the G_GAIN less 2 ft-L than brightness of procedure for 9300K.
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CONFIDENTIAL 4 Alignment and Adjustments CONDITIONS PROCEDURE Scanning frequency: 91 kHz / 85 Hz 1. Adjust the Focus VR on the FBT to display the Display image: Full white pattern sharpest image possible. Brightness: Cut-off 2. Use Locktite to seal the Focus VR in position. Contrast: Maximum 4-3-7 Color Purity Adjustment...
CONFIDENTIAL 5 Troubleshooting 5-1 Parts Level Troubleshooting Notes: 1. If a picture does not appear, Click the Brightness and Contrast button on the front panel, and then increase the value of Brightness and Contrast. 2. Check the following circuits. • No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit. •...
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CONFIDENTIAL 5 Troubleshooting 5-1-2 PFC Failure Check the Voltage at IC701 Pin5. Check and Replace D702, The Voltage is around 10V R711, ZD705, ZD706. Q701 Gate waveform is right? Replace IC701. Check the Voltage at D701 cathode. Replace Q701, D701. The Voltage is about 400V Done.
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CONFIDENTIAL 5 Troubleshooting 5-1-5 S Correction Failure Check S1 ~ S6 signal. Refer to the S-corrction table page? S1~S6 signals are right at Check and replace IC201. each frequency block? Check and replace C411, C414, C415, C416, C417, C418,C419, Q403 ~ Q407, Q408 ~ Q412, Q413, Q414. 5-1-6 H_Lin.
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CONFIDENTIAL 5 Troubleshooting 5-1-8 Abnormal H_Size WAVEFORMS The Voltage waveforms at Repeat the troubleshooting Q402, Collector Q402 Collector are right? Guide of H_deflection failure. T402 pin 8 wareform is right? Replace T402. T402, #8 Check some parts around IC250 and IC402 Pin 1 and 2. 5-1-9 Side Pin or Trap Failure IC250 Pin 24 output exists? Check and replace IC250.
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CONFIDENTIAL 5 Troubleshooting 5-1-11 Tilt Failure Check tilt connector connection IC201 Pin 19 output duty varies Check and replace IC201. with different DAC values? IC403 Pin 10, 11 output varies with Check and replace IC403. different DAC values? Check and replace CRT. 5-1-12 V Deflection Failure WAVEFORMS Is 14V at IC301 Pin 2?
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CONFIDENTIAL 5 Troubleshooting 5-1-13 V Size or Pos. Variation Failure IC250 Pin 23 output varies with Check some parts around IC250. different DAC values? Check bias voltage. Check and replace IC250 and IC301. 5-1-14 High Voltage Failure Check +12 V line. WAVEFORMS Q504 gate driving pulse exist? Check and replace...
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CONFIDENTIAL 5 Troubleshooting 5-1-15 ABL Failure Input full white pattern to monitor. IC102 Pin12 input exists and Check and replace IC102. varies with different patterns? Check CN102, Q101, Q102, ZD101. T501 Pin 8 Voltage exists? Check and replace T501. IC103 Pin 16 output exists and Check and replace IC103.
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CONFIDENTIAL 5 Troubleshooting 5-1-17 No Video WAVEFORMS Check signal cable and connection. CRT Socket, Red, Green, Blue IC101 Pins 1, 3 and 5 Check CN101, IC1, QR51, QG51, inputs are right? QB51, and IC3 on BNC Board. IC101 Pins 20, 22 and 24 Check Vcc on IC101 and replace IC101.
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CONFIDENTIAL 5 Troubleshooting 5-1-18 Micom Failure WAVEFORMS IC201 Pin 35 input is over 4.2V? Check IC650. 3.42 V (IC201, #8) IC201 Pin 8 and 9 Check X201, C203 and C204. 16 17 inputs are right? CH1 P-P = 3.42 V CH1 RMS = 2.500V All in/output values are right? Replace IC201.
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CONFIDENTIAL 5 Troubleshooting 5-1-20 User Control Failure Check connector Ass’y. IC201 Pins 16 and 17 inputs are Check and replace function key. right at each function? Check and replace IC201. Done. 5-1-21 Degaussing Failure Check degaussing connector. RL601 operation is right? Check D-Coil, POS601.
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CONFIDENTIAL 5 Troubleshooting 5-2 General Troubleshooting 5-2-1 No Picture WAVEFORMS Go to 5-2-2 Shut down LED blinks? troubleshooting guide. R, G, B, Video Check D598, D599 and G2 wire. G2 Voltage is right? Also check around FBT circuits. Heater Voltage is right? Check CN201 Assy and D642, Q672.
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CONFIDENTIAL 5 Troubleshooting 5-2-3 Missing Color Proper Video levels are Check signal generator and on CN101 Pin 1, 3 and 5. replace BNC Board. Proper AC voltage are Refer to 5-1-17 No Video. on all cathodes? Proper DC voltage are Check IC105 Pin 1, 3 and 5.
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CONFIDENTIAL 5 Troubleshooting 5-2-4 Visible Retrace Check white balance adjustment. G2 voltage is right? Check G2 control volume and FBT. Blank pulse is on Pin 23 of Check CN102, Q104. IC102 on Video board? Blank pedestal is on Check IC102 and related Pin 25, 28 and 30 of IC102 ? components.
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CONFIDENTIAL 5 Troubleshooting 5-2-5 Unsynchronized Image Compare input sync. of IC201 Pin 41 and 42 with output sync. of IC201 33 and 34. Are they all right? Check and replace IC201. Are H_Out and V_Out Check and replace IC250. of IC250 Pin 23 and 26 right? Are H_FLYBACK of Check CN102 Assy and Q103.
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CONFIDENTIAL 5 Troubleshooting 5-2-6 Misconvergence Are the C/G control circuits in the video Board? Check the C/G control Assy Try readjusting convergence. (CN104, CN105). Proper voltage are appeared Check and replace IC106. The convergence is on IC106 Pin 7, 8, 10, and 11 now within spec.? in Video Board.
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CONFIDENTIAL 5 Troubleshooting 5-2-7 Poor Focus Adjust focus VR. Aging monitor and Improved focus? check for focus change. Check focus leads from FBT to CRT Socket. Check the CRT Socket. Refer to 5-1-16 Dynamic Dynamic focus circuit is right? Focus Failure. Replace the CRT and verify focus.
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CONFIDENTIAL 5 Troubleshooting 5-2-9 No Operating High Light Zone WAVEFORMS Change the video signal to windows pattern. IC101, #14, 15 Does not the High Light Done. Zone appear? Are the waveforms right Check connection Assy (CN102). on IC101 Pin 14 and 15? IC101, #18 Is the waveform right on Check and replace IC103.
CONFIDENTIAL 7 Electrical Parts List ❈ You can search for updated part codes through ITSELF web site. URL : http://itself.sec.samsung.co.kr/ 7-1 Main PCB Parts Loc. No. Code No. Description Specification Remarks BH94-00825A ASSY PCB MAIN CF21GS C414 2306-000102 C-FILM,MPPF 1.2uF,5%,250V,TP,29*31*14.5,20...
CONFIDENTIAL 10 Schematic Diagrams 10-1-1 Main Part Schematic Diagram CEPHEUS PROJECT POWER CIRCUIT WARING: BEFORE SERVICING THIS CHASSIS, SCHEMATIC DIAGRAM (1) CAUTION READ "X-RAY RADIATION PRECAUTION,SAFETY WARNING: "THIS EQUIPMENT CONTAINS SAFETY MODEL: 1. THE AREAS MARKED WITH A IN THE SCHEMATIC CRITICAL COMPONTS ALL PARTS SHOWN IN THE SHADED PRECAUTION, PRODUCT SAFETY NOTICE".