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FILE NO. SM-CTV-O-158
COLOR TELEVISION

SERVICE MANUAL

MODEL NO. 14BM18
CHASSIS NO. EX-1A3
Please read this manual carefully before service

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Summary of Contents for Digital Equipment 14BM18

  • Page 1: Service Manual

    FILE NO. SM-CTV-O-158 COLOR TELEVISION SERVICE MANUAL MODEL NO. 14BM18 CHASSIS NO. EX-1A3 Please read this manual carefully before service...
  • Page 2: Table Of Contents

    TABLE OF CONTENTS SPECIFICATIONS ·················································································································· SAFETY INSTRUCTIONS AND MAINTENANCE ········································ X-RAY RADIATION PRECAUTION ··································································································· SAFETY PRECAUTION ···················································································································· PRODUCT SAFETY NOTICE ··········································································································· SAFETY SYMBOL DESCRIPTION ··································································································· MAINTENANCE································································································································· ADJUSTMENTS ······················································································································ SET-UP ADJUSTMENTS ·················································································································· CIRCUIT ADJUSTMENTS················································································································· STRUCTURE AND CHASSIS FUNCTION DESCRIPTION ··············· STRUCTURE BLOCK DIAGRAM···································································································...
  • Page 3: Specifications

    SERVICE MANUAL SPECIFICATIONS Model Number 14BM18 Color system PAL4.43, NTSC3.58, NTSC4.43, SECAM RF system Sound system B/G, I, M, D/K C1 C12 (49.75-85.25MHz, 168.25-216.25MHz) Receiving C13 C57 (471.25-863.25MHz) channel Z1 Z7 (111-167MHz) CATV Z8 Z35 (223-447MHz) Programs preset 236(0-235) Antenna input 75 (unbalanced) Picture tube (Approx.)
  • Page 4: X-Ray Radiation Precaution

    SERVICE MANUAL INSTRUCTIONS FOR SERVICE SAFETY AND MAINTENANCE WARNING: BEFORE SERVICING THIS CHASSIS, READ THE X-RAY RADIATION PRECAUTION , SAFETY PRECAUTION AND PRODUCT SAFETY NOTICE INSTRUCTION BELOW. X-RAY RADIATION PRECAUTION 1. The EHT must be checked every time the TV is serviced to ensure that the CRT does not emit X-ray radiation as result of excessive EHT voltage.
  • Page 5: Product Safety Notice

    SERVICE MANUAL 5. Do not use a magnetized screwdriver when tightening or loosing the deflection yoke assembly to avoid electronic gun magnetized and decrement in convergence of the CRT. 6. When remounting the TV chassis, ensure that all guard devices, such as nonmetal control buttons, switch, insulating sleeve, shielding cover, isolating resistors and capacitors, are installed on the original place.
  • Page 6: Maintenance

    SERVICE MANUAL working on the TV with the back removed. This is an international hazard symbol, telling you that the components identified by the symbol have special safety-related characteristics. This symbol tells you that the critical components identified by the FDA marking have special safety-related characteristics.
  • Page 7: Adjustments

    SERVICE MANUAL ADJUSTMENTS SET-UP ADJUSTMENTS The following adjustments should be made when a complete realignment is required or a new picture tube is installed. Perform the adjustments in the following order: 1. Color purity 2. Convergence 3. White balance Notes: The purity/convergence magnet assembly and rubber wedges need mechanical positioning.
  • Page 8 SERVICE MANUAL Dummy Wedge Deflection Coil Rubber Wedge Adhesive Purity/Convergence Deflection Yoke Magnet Module Glass Cloth Tapes Fig. 1 6-pole Magnet Fixed 4-pole Magnet Adjust the Angle (Vertical Lines) Rotate Two Tabs At the Same Time (Horizontal Lines) Purity Magnet Adjustment of Magnets Convergence Magnet Assembly Fig.
  • Page 9 SERVICE MANUAL obtained. 2.2 Circumference convergence adjustment 2.2.1 Loosen the clamp screw holding the deflection yoke assembly and allow it tilting. 2.2.2 Temporarily put the first wedge between the picture tube and deflection yoke assembly. Move front of the deflection yoke up or down to obtain better convergence in circumference. Push the mounted wedge in to fix the yoke temporarily.
  • Page 10: Circuit Adjustments

    SERVICE MANUAL CIRCUIT ADJUSTMENTS Preparation: Circuit adjustments should be made only after completion of set-up adjustments. Circuit adjustments can be performed using the adjustable components inside the TV set. For TVs with C bus control, first change the bus data. 1.
  • Page 11 SERVICE MANUAL FBT. 4.2 Power on the TV and preheat it for 15 min. 4.3 Receive a normal TV signal. Rotate knob of the FCB until you get a sharp picture. 5. Safety Inspection 5.1 Inspection for insulation and voltage-resistant Perform safety test for all naked metal of the TV.
  • Page 12 SERVICE MANUAL Horizontal center in the TV mode for 50Hz/60Hz 5HSH/6H For 50Hz, 5HSH is displayed for 60Hz, 6HSH optimal mode is displayed. 5EWW/6 East-West correction (for large-screen only) 5EWP/6 East-West parabola correction (for large-screen only) 5UCR/6 Upper corner parabola correction (for large-screen only) 5LCR/6L Lower corner parabola correction (for large-screen...
  • Page 13 SERVICE MANUAL IFFS PIF (02-38.9MHz, 03-38MHz) 03 02 HDOL 00-07 Cathode drive level (typical: 04-07) IF ACG speed VG2 brightness setting(VG2B): 3A for 21” models; 2E for 14” models; Contrast Max. setting (MCON): 30 for 21” Malaysia VG2B Matsushita or BMCC CRT with ferrite mask; MCON: 30;...
  • Page 14 SERVICE MANUAL Table 2 Function Option Bit Setting Item Description Data OP_HOTEL Hotel mode (1: Yes, 0: No) Channels preset: 1: 236 channels OP_236 0: 100 channels OP_NTSC NTSC color system options: 1: Yes, 0: No Two sets of AV inputs: 1: Two sets of separate AV inputs OP_AV2 0 Two sets of parallel AV inputs or one set of AV inputs OP-SVSH...
  • Page 15 SERVICE MANUAL Memory power-on (If turned off by the remote control, OP_DIRECT_SW then the TV is turned on by the remote control; if turned ITCH_ON off by the MAIN POWER SWITCH, then turned on by the MAIN POWER SWITCH.) 1: Yes OP_HCO EHT tracking mode Changhong logo display...
  • Page 16 SERVICE MANUAL Sound system options external circuit OP_EXT_SIF0 (OP-EXT-SIF1/0): D/K: 00 B/G: 01 I: 10 M: 11. 1: Sets sound system of external SIF as the appropriate OP_EXT_SIF1 one and also sets sound system in the course of auto demo as the appropriate one 0: Changes sound system in the course of auto demo.
  • Page 17: Structure And Chassis Function Description

    SERVICE MANUAL STRUCTURE AND CHASSIS FUNCTION DESCRIPTION 1. STRUCTURE BLOCK DIAGRAM From IF Pre- Antenna Tuner Amplifier A101 AV IN SAWF Band 1,2 Vt,AGC AV OUT EEPROM IIC BUS AT24C08 Video Amplifier Microcontroller and small signal processor Formed of Rem ote R e m o t e CH05T0101 VY01-VY09...
  • Page 18: Block Diagram For Supply Voltage System

    SERVICE MANUAL 2. BLOCK DIAGRAM FOR SUPPLY VOLTAGE SYSTEM VD491 +190V To CRT RGB PCB VD451 +45V To A100,N401 VD461 +16V T400 To N401 VD471 To A100, N100, N442 +115V VD891 VD871 +16-S +5V-2 N441 To A100 To N600B Bridge Rectifying Power Regulat ion Switch Filter...
  • Page 19: Chassis Description

    SERVICE MANUAL 3. CHASSIS DESCRIPTION 1). General Description EX-1A3 chassis series are applied in 14BM18 respectively which uses mainly Philips’ advanced UOC-ultimate chip TDA935X/6X/8X and I C-bus controlled IC. With combination of microcontroller small signal processor, TDA935X/6X/8X series feature high-integration, high-performance-to-price ratio and high-reliability and advanced functions with fewer external components, which provide much convenience for manufacturing and technical service.
  • Page 20: Service Data

    SERVICE MANUAL SERVICE DATA 1. KEY ICS TECHNICAL DATA 1.1 Microcontroller and small signal processor TDA935X/6X/8X The super chips TDA935X/6X/8X are good in pins compatibility. Differences among them are shown as follows. TDA9351 48K PAL/NTSC/SECAM+1 PAGE TELETEST TDA9350 48K PAL/NTSC+1 PAGE TELETEST TDA9361 64K PAL/NTSC/SECAM+10 PAGE TELETEST TDA9360 64K...
  • Page 21 SERVICE MANUAL Internal base-band delay line RGB control circuit with ‘Continuous Cathode Calibration’, white point and black level offset adjustment so that the colour temperature of the dark and the light parts of the screen can be chosen independently. Linear RGB or YUV input with fast blanking for external RGB/YUV sources. The Text/OSD signals are internally supplied from the -Controller/Teletext decoder Contrast reduction possibility during mixed-mode of OSD and Text signals Horizontal synchronization with two control loops and alignment-free horizontal oscillator...
  • Page 22 SERVICE MANUAL Signal quality detector for video and WST/VPS data types Comprehensive teletext language coverage Full Field and Vertical Blanking Interval (VBI) data capture of WST data Display Teletext and Enhanced OSD modes Features of level 1.5 WST and US Close Caption Serial and Parallel Display Attributes Single/Double/Quadruple Width and Height for characters Scrolling of display region...
  • Page 23 SERVICE MANUAL 3) Block Diagram...
  • Page 24 SERVICE MANUAL...
  • Page 25 SERVICE MANUAL 4) pinning Table 5 SYMBOL DESCRIPTION P1.3/T1 port 1.3 or Counter/Timer 1 input P1.6/SCL port 1.6 or I C-bus clock line P1.7/SDA port 1.7 or I C-bus data line P2.0/TPWM port 2.0 or Tuning PWM output P3.0/ADCO/PWMO port 3.0 or ADC0 input or PWM0 output P3.1/ADC1/PWM1 port 3.1 or ADC1 input or PWM1 output P3.2/ADC1/PWM2...
  • Page 26 SERVICE MANUAL SYMBOL DESCRIPTION B2/UIN 2nd B input/U (B-Y) input BCLIN beam current limiter input/(V-guard input, note2) BLKIN black current input/(V-guard input, note2) Red output Green output Blue output VDDA analog supply of Teletext decoder and digital supply of TV-processor (3.3V) OTP programming Voltage VDDC...
  • Page 27 SERVICE MANUAL Fig.8 Pin Configuration (SDIP 64)
  • Page 28 SERVICE MANUAL 1.2 5 W Mono BTL Audio Amplifier with DC Volume Control TDA7056B (1) Features (2) General Description · DC volume control The TDA7056B is a mono Bridge-Tied Load (BTL) · Few external components output amplifier with DC volume control. ·...
  • Page 29 SERVICE MANUAL 1.3 Vertical scan output stage circuit TDA8356/N6 DC-coupled vertical deflection circuit TDA8356 1) Features Few external components Highly efficient fully DC-coupled vertical output bridge circuit Vertical flyback switch Guard circuit Protection against: Short-circuit of the output pins (7 and 4) Short-circuit of the output pins to VP.
  • Page 30 SERVICE MANUAL 1.4 EEPROM AT24C08 1) Features Data EEPROM internally organized as 1024/2048 2) Pin Configuration bytes and 64/128 pages×16 bytes Page protection mode, flexible page-by-page hardware write protection -Additional protection EEPROM of 64/128 bits, bit per data page 1-Protection setting for each data page by writing its protection bit -Protection management without switching WP pin Low power CMOS...
  • Page 31 SERVICE MANUAL 1.5 Power module STR-G5653/6454R Switch-mode Power Supply STR- G5653/F6654 The Series STR-G5653/F6654 is specifically designed to satisfy the requirements for increased integration and reliability in off-line quasi-resonant flyback converters. The series incorporates a high-precise error amplifying control and drive circuit with discrete avalanche-rated power MOSFET, featuring fewer external components, small-size and standard power supply.
  • Page 32 SERVICE MANUAL 3). Pin Configuration and Functions Fig.16 Table 9 Pin function for STR-G5653 Pin No. Symbol Function Description MOSFET drain MOSFET source Ground Supply voltage input for control circuit OCP/FB Over-current protection detection signal/ voltage-limiting signal input Table 10 Pin function for STR-F6654 Pin No.
  • Page 33: Waveforms Of Key Points

    SERVICE MANUAL 2. WAVEFORMS OF KEY POINTS NI00 NI00 Pin58 Pin33 NI00 NI00 Pin34 Pin44 NI00 NI00 Pin21 Pin22 BU250 BSC60H 8DX-B -HEAT...
  • Page 34 SERVICE MANUAL BCT-4 N100 Pin4 -P40 Notes: The waveforms are only for reference. The waveforms may differ dependent on different models.
  • Page 35 SERVICE MANUAL 3. KEY ICS SERVICE DATA Table 11 Function and Service Data of TDA7056B (N600B)’s Pins Digital Multimeter Function Description Reference Voltage (V) Positive Resistance (20K ) Negative Resistance (20K ) Not connected Positive supply voltage Voltage input Signal ground DC volume control Positive output Power ground...
  • Page 36 SERVICE MANUAL VSSC/P P0.5 0.01 13.3 13.3 P0.6 11.6 11.0 VSSA SECPLL 27.6 21.7 DECDIG 23.1 16.1 PH2LF 27.5 `21.0 PH1LF 27.9 21.2 GND3 DECBG 24.4 18.7 AVL/EWD (1) 0.01 27.6 21.2 VDRA 27.6 20.4 IFIN1 27.6 20.3 IFIN2 24.7 19.8 IREF 24.7...
  • Page 37 SERVICE MANUAL BCLIN 27.6 20.8 BLKIN 27.9 21.3 VDDA 11.0 11.3 VDDC 11.0 11.3 OSCGND 0.02 XTALIN XTALOUT RESET VDDP 11.0 11.3 P1.0/INT1 P1.1/T0 P1.2/INT0 18.2 17.5 Table 14 Functions and Service Data of AT24C08 (N200)’s Pins Digital Multimeter Function Description Reference Voltage (V) Positive Resistance (20K ) Negative Resistance (20K )
  • Page 38: Replacement Of Parts

    SERVICE MANUAL 4. REPLACEMENT OF PARTS 4.1 Description Many electrical and mechanical components in this chassis have special safety-related characteristics. Components which have these special safety characteristics in this manual and its supplements are identified by the international hazard symbols or UL, FCC, FDA or VDE marking on the circuit diagram and parts list.
  • Page 39 Circuit Diagram for 14BM18...
  • Page 40 CRT RGB PCB (For IRICO CRT only) (For BMCC CRT or Indonesia-based LG CRT or THAI CRT or Chunghwa CRT only)
  • Page 41 Final Assembly Diagram for 14BM18 Warning label Certification Wire clip XJ-100 Rubber washer M5 notched washer nut Tapping screw 4X20BAHCh Tapping screw 3X12VwAHCh Tapping screw 3X10KTHCh Rear plate Side-set AV plate AV plate Wire clip Wire clip A Distance clip...
  • Page 42 Final Wiring Diagram for 14BM18 Side-set AV PCB Assembly Side-set AV PCB Assembly Wired Connector XS161 Wired Connector XS161 Wired Connector XPY01 Wired Connector XPY01 CRT RGB PCB Assembly CRT RGB PCB Assembly W01.000;6 W01.000;6 W01.000;1 W01.000;1 W01.000;4 W01.000;4 Main PCB Assembly...

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