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Related Manuals for Tatung C7BTR Series
Summary of Contents for Tatung C7BTR Series
- Page 1 Tatung C7BTR SERIES Low Radiation Extended VGA PLUG & PLAY COLOUR MONITOR SERVICE MANUAL...
- Page 2 TABLE OF CONTENTS PAGE 1. Precautions and notices……………………………………1 2. Specification……………… ………………………………3 3. Control Location and Functions …………………………. 5 4. Disassembly instructions ………………………………… 7 5.General Connections & applications…. …………………. 10 6.Electronic Circuit Description …………………….………12 7.Adjustment ……………………………………..…………24 8.Troubleshooting follow Chart …..………………….……. 30 9.Black Diagram …………………..……………………….
- Page 3 1. PRECAUTIONS AND NOTICES 1-1 SAFETY PRECAUTIONS 1) Observe all cautions and safety related notes located inside the display cabinet and on the display chassis. 2) Operation of these displays outside the cabinet of with the cover removed involves a shock hazard from the display power supplies. Work on the display should not be attempted by anyone who is not thoroughly familiar with precautions necessary when working on high voltage equipment.
- Page 4 Connect the monitor power lead to the mains supply, via an isolation transformer, and switch on, Using the test circuit shown in Fig1-1 measure the AC leakage current between each pole (L and N) of the supply and all accessible metal parts. The earth leakage current must not exceed 3.5mA 1-2 product safety notice Many electrical and mechanical parts in this chassis provide special visual safety protection .
- Page 5 5. General Connection & Applications Procedure for installing and using this model of ultra Super-VGA color display . 1. Set up the display at the desired operation location , on top of or beside your personal computer . Plug the power cord into the monitor and then connect the other end of the power cord into an AC outlet .
- Page 6 2. Specifications Display CRT Size 17” CRT Dot Pitch 0.27mm View-able Diagonal Area 15.9” Max. Resolution Mode 1280×1024 @ 60Hz Non-Interlaced Display Area 12.05”×9.05” (306mm ×230mm) Signal Video Signal Level Analog 0.7 Vp-p / 75 ohm Synchronization H/V Separate( TTL ) positive Signal Connector 15-pin mini D-sub Frequency...
- Page 7 Time Table For Sync. Signal Mode No. Unit Resolution 640×480 720×400 640×480 800×600 640×480 Horizontal Frequency 31.468 31.468 37.500 37.878 43.269 (A)Horizontal 31.778 31.778 26.667 26.4 23.1 usec (B ) Horizontal Pulse Width 3.813 3.813 2.032 1.556 usec (C ) Horizontal Back Porch 1.907 1.907 3.810...
- Page 8 6. ELECTRONIC CIRCUIT DESCRIPTION 6-1. Switching Mode Power Supply (SMPS) The switching mode power supply for this monitor is a full range type. Universal power input of AC 100V ~ 240V is compatible. The AC input is supplied through the slow blow fuse F801, the first line T802, the signal pole power switch S801 to the rectifier D811 ~D814.The rectified DC voltage is about 125V ~ 335V and is fed to the switching transformer T801 via R808.
- Page 9 However, in order to allow auto-recovery from power saving off state, the SMPS circuit is designed as an unlatched type, the DC current flows via R849 Q850, R850 to charge C866A again, when the voltage across C866A has reached 16V, I862 is turned on again. Once the peak voltage across R867 is over 1Vp-p, I862 will be forced off again.
- Page 10 Heater voltage The heater element in the CRT is supplied with 6.3+0.3V during normal operation of the monitor and 5.0+0.5v during suspend mode. To achieve the goal, Q851, D871 and associate circuit is introduced when at normal state, a Horizontal pulse is fed to D871 via P807, Q851 is on, the feedback voltage on pin 2 of I862 is normal, the output voltage of the secondary side of T801 is normal the heater voltage is 6.3V + 0.3V.
- Page 11 The CPU will be reset when the power is on. The components R506; D506 and C506 on pin4 of I501 ensure correct start. The +5V voltage is fed into I501 via pin5; an 8MHz resistor is connected on pin7, pin8 of I501 to generate the CPU clock for the software execution.
- Page 12 then release the " < " key, the monitor should now be in the factory setting mode (OSD in black ground with red edge). All adjustment data will be stored automatically, and then power on again, the monitor will reverse to normal operating state. 6-6.
- Page 13 I-SENSE Sensing of External B+ Switching MOSFET Q440 Source Current B+GND Ground (related to B+ reference adjustment) BREATH DC Breathing Input Control V-GND Vertical Selection Signal Ground VAGC-CAP Memory Capacitor for Vertical AUTO-GAIN Control Loop in Vertical Ramp Generator VREF Vertical Section Reference Voltage (to be filtered) V-CAP Vertical Saw-tooth Generator Capacitor...
- Page 14 6-8. Vertical Deflection Circuit The power amplifier driving the vertical yoke assembly is a DC design-based on power amplifier I330 TDA8172. The vertical deflection coil is connected to pin5 of I330 via P440. The saw- tooth signal is derived from pin3 of I401 and fed to pin1 of I330 via R330 / C330. The DC bias voltage is derived from pin21 of I401 and fed to pin7 of I330 via divider R348 / R347 to optimize the vertical position.
- Page 15 Linear coil Input Frequency 62K-70K 53.4K-62K 45K-53.4K 42.4K-45K 36.4K-42.4K 27.9K-36.4K 6-10. Horizontal Width Control The monitor uses a diode modulation circuit for the control of width. It is achieved by changing the base voltage of Q467 to have influence on the base of Q470. The DC control voltage (0V ~5V) is derived from pin2 of CPU I501 via Q502;...
- Page 16 6-12. Video Circuit There are three the ICs applied for the video circuit. I901 is a three channel pre-amplifier IC; I903 is OSD (On Screen Display) feature IC and I904 is for video output amplifier IC. The analog R. G. B. video input signals are supplied through the cable, which is terminated at P901, these input signals are approximately 0.7Vp-p in amplitude.
- Page 17 6-13. Spot Killer Circuit The spot killer circuit is included, in order to eliminate damage of the CRT while switching power on or off. The -225V is obtained from the voltage on pin7 of T440 via D489. When power is on both +75V and -150V will charge on C349 via D349, at this moment Q348 is off. When power is off, the positive end of C348 is ground and Q348 is on, -225V is fed to G1 via Q348, R348A, and D357 cutoff the beam current.
- Page 18 A square waveform control signal on pin28 of I401 is then fed to Q440 via buffer Q438, Q439/ Q440 is designed as a step-up voltage converter and the DC voltage is fed to the Drain of Q440 via L440. The energy is stored in L440 when Q440 is on; the energy is released when Q440 is off. The circuit supplies DC voltage (60V ~ 190V) to pin9 of T440 via Q440 and D442.
- Page 19 A7. ADJUSTMENT S801- - - -Power Switch MAIN BOARD (Component side view) PWB-- - -0176 S516---Control key R833- - - -B+ Adjust R321- - - -HV Adjust R471- - - -ABL Adjust R482- - - -SUB Brightness Adjust S801 CRT DRIVE BOARD (Component side view) PWB-0173 FOCUS1 FOCUS2...
- Page 20 Controls on front panel Function 1. Power LED This indicator will light when the power is ON and the power cord is properly connected. The state of the LED is dependent on the Power State of the monitor. When the LED is green, the monitor is in the normal state., It indicates a power saving state.
- Page 21 8. TROUBLESHOOTING FLOW CHART (1) Power Start NG Power start Is the voltage at C815 normal (125-340V) F801 open ? Does R808 open? Check power socket copper and plug & D811~D814, R805 Check Q868,I862,D831,R867 Is the start-up voltage at C831(16V) Check R849, R848, D870, C831, D831, R831,Q850,D848 Is the...
- Page 22 (2) No Data Appear No data appear Are the waveforms at pin 2,6,11 of I901 Normal Check signal cable, C901, C931, C961 Are the voltages at pin 15 of I901 normal Check ABL line from PCB Are the waveforms at pin 35,32,29 of I901 normal The voltage at...
- Page 23 (3) No Raster appear No raster the H.V. correct Does raster light up with SCREEN control turned clockwise Is the Reset SCREEN voltage at O/P control. of D442 normal (80-190V)? Is the Check PWM B+ voltage at CKT Q440, Q438, heater normal Q439, D442, C435, (6.3V) ?
- Page 24 (5) Loss of Vertical Synchronization Loss of vertical synchronization (4) R/G/B is Missing R/G/B is Is the waveform at Pin 32 of I501 normal ? Is the Check I401 waveform at Pin 2/6/11 of I901 normal Check signal cable. Is the C901/C931/C961 waveform at Pin 40 of I501...
- Page 25 Are the voltages at Pin 2 of I330 14V Pin 4 of I330 -9V Is the voltage at Pin 7 of I330 normal (1.8V) ? Is the Check R347, R348 waveform at Pin 23 of I401 normal voltage at Pin 22 of I401 normal Check C302, C338, R347,...
- Page 26 (8) MICRO CONTROL FUNCTION ABNORMAL MICRO CONTROL ABNORMAL Is the control function working ? Is the sync signal on Pin 39/40 normal Check S509 - S512 R571 - R580 Check Q550, C512, C514, I502 Q556 Check 5V on Pin 5 of I501 Check X510, D506, C506 (9)HORIZONTAL WIDTH CONTROL ABNORMAL H.
- Page 27 Disassembly Instructions Caution : When servicing or replacing the CRT Disconnect the 1. Face Down The Monitor ( Fig 4-1) . Anode and Discharge the Anode shield completely. 2. Back Cover Removal As high voltage (26KV) may remain on the Anode a) Remover 4 screws ( A ) from the for an extended time after power off .
- Page 28 ( Fig. 4-5 ) ( Fig. 4-6 ) b) Remove 2 screws from the bezel . ( Fig4-6 ) to move the CRT . c) Remove the volume control board from CAUTION : Do not lift the CRT by the neck . the bezel .