This document is a service manual for a Samsung Color Television Receiver, model CK20F1VR5X/BWT, with chassis S15A. It provides comprehensive information for servicing and maintaining the device.
Function Description
The Samsung Color Television Receiver is designed to display color television broadcasts. It supports various television systems including PAL-I (VHF/UHF), PAL-B/G, SECAM-B/G, PAL-B/G, D/K, SECAM-B/G, D/K, PAL-B/G, D/K, SECAM-B/G, D/K, NT 4.43, and PAL-B/G, D/K, SECAM-B/G, D/K, NT4.43, NT3.58. It also supports NTSC-M. The television includes features for audio output, with speaker impedance options of 8 ohm, 5W+5W (Dual Type) or 16 ohm, 3W (Monitor Type & Dual Type). It has an antenna input impedance of 75 ohm (unbalanced type) for VHF/UHF signals.
Important Technical Specifications
Television Systems:
- CI: PAL-I (UHF)
- CII: PAL-I (VHF/UHF)
- CX: PAL-B/G, SECAM-B/G
- CK: PAL-B/G, D/K, SECAM-B/G, D/K
- CW: PAL-B/G, D/K, SECAM-B/G, D/K, NT 4.43
- CS: PAL-B/G, D/K, SECAM-B/G, D/K, NT4.43, NT3.58
Channels:
- VHF: 2 - 12 (PAL/SECAM-B/G,I), 1 - 13 (PAL-SECAM-D/K), 2 - 9 (SECAM-K1, PAL-D), 2 - 13 (NTSC-M)
- UHF: 21 - 69 (PAL/SECAM-B/G,I), 21 - 69 (PAL-SECAM-D/K), 13 - 57 (SECAM-K1, PAL-D), 14 - 69 (NTSC-M)
Intermediate Frequencies (MHz):
- Picture IF Carrier: 38.90 (all systems)
- Sound IF Carrier: 33.40 (PAL/SECAM-B/G,I), 32.40 (PAL-SECAM-D/K), 32.90 (SECAM-K1, PAL-D), 34.40 (NTSC-M)
- Color Sub Carrier: 34.47 (PAL/SECAM-B/G,I), 34.47 (PAL-SECAM-D/K), 34.47 (SECAM-K1, PAL-D), 35.32 (NTSC-M)
Picture Tube:
- 14 Inch: A34KQV42X (Quick start, in-line-gun)
- 20 Inch: A48KRDB2X(H) (Black stripe, 90°degree deflection)
- 21 Inch: A51KQJ63X
Power Requirements:
Antenna Input Impedance:
- VHF, UHF: Telescopic dipole antenna (75 ohm unbalanced type)
Speaker Impedance:
- 8 ohm, 5W+5W (Dual Type)
- 16 ohm, 3W (Monitor Type & Dual Type)
Semiconductor Base Diagrams:
The manual includes diagrams for various semiconductors used in the television, such as electrolytic condensers, diodes, ICs (e.g., TDA884X, TDA8910, SAAS291, KS24C040, UPC574J, KA33V), transistors (e.g., 2SD1651, KSD1650, KSD9072, KSD1710, KSD1711, KSC5386, KSC5315, KSA539, BC548, KTC9014, TDA8133, TDA6107Q, TDA6101Q, KA7630, KSR1012, KSR2010, KSD82010, KTD863-Y), and SAW-filters (K2971M, K7252M).
Usage Features
The television is designed for ease of use with a remote control. It supports various picture and sound adjustments. The "Factory Mode" allows for detailed adjustments of parameters such as Auto Gain Control, Voltage Control Oscillator, Sub Bright, Sub Contrast, Sub Color, S-Correction, Red Drive Gain, Green Drive Gain, Blue Drive Gain, Cathode Drive Level, Blue Stretch Mode, PAL Vertical Slope, PAL Vertical Shift, PAL Vertical Amplitude, PAL Horizontal Shift, NTSC Sub Color, Sub Tint, and TTX Sub-Contrast. These parameters are aligned using 50Hz vertical-field rates.
The television also supports different option bytes for various regions and broadcast standards (e.g., China, Singapore, Germany, United Kingdom, France/Switzerland, Eastern Europe, Russia/CIS, Australia, India, Middle East/Africa, Vietnam/Malaysia). These option bytes configure the TV for specific regional requirements, including TV/AV modes, sound systems, color systems, and language settings.
The remote control allows access to the "Service Mode" for adjustments, with options for "SLEEP→FACTORY" and "STAND-BY→DISPLAY→P.STD→MUTE→POWER ON". Adjustments can be made using the VOLUME keys (Up or Down) and CHANNEL keys (Up or Down).
Maintenance Features
Safety Precautions:
The manual emphasizes several safety precautions for servicing:
- Always use built-in protective devices and replace missing protective shields.
- Reinstall all protective devices, including nonmetallic control knobs and compartment covers.
- Ensure no cabinet openings allow children to insert fingers or contact dangerous voltages.
- Measure resistance between the picture tube and the cabinet mask, and between the cabinet ventilation slots and improperly fitted back covers to ensure it's less than 1.0 megohm.
- Perform a Leakage Current Hot Check using an isolation transformer and a metering system that complies with National Standards Institute (ANIS C101.1), Leakage Current for Appliances (UL Publication UL1410), and Underwriters Laboratories (UL Publication UL114). The current measured should not exceed 0.5 milliampere.
- When replacing parts, use only specified components to prevent damage and potential hazards.
- Always use an AC adapter plug connected from the AC source to connect an electrical jumper across the two AC prongs.
- Discharge the anode cap of the picture tube before removing it.
- Use only a grounded-tip soldering iron when soldering or unsoldering ESDs.
- Do not remove a replacement ESD from its protective package until you are ready to install it.
- Minimize body motions when handling unpackaged replacement ESDs.
- Always connect a test instrument's ground lead to the instrument chassis ground before connecting the positive lead.
Servicing Precautions:
- Servicing precautions are printed on the cabinet.
- Always unplug the unit's AC power cord from the AC power source before attempting to remove or reinstall any component or assembly, or disconnect an electrical plug or connector.
- Some components are raised above the printed circuit board for safety.
- After servicing, always check that the screws, components, and wiring have been correctly reinstalled.
- Check the insulation between the blades of the AC plug and accessible conductive parts.
- Perform an Insulation Checking Procedure: Disconnect the power cord from the AC source and turn the power switch ON. Connect an insulation resistance meter (500V) to the blades of the AC plug. The insulation resistance between each blade of the AC plug and accessible conductive parts should be greater than 1 megohm.
- Never defeat any of the B+ voltage interlocks.
- Always connect a test instrument's ground lead to the instrument chassis ground before connecting the positive lead.
Disassembly and Reassembly:
The manual provides detailed instructions for disassembly and reassembly of the television:
- Back Cover Removal: Remove screws, press the tension rib, and pull the cabinet backwards.
- Main Board Removal: Separate the socket board from the CRT neck, remove the Anode Cap from the CRT, and remove the main board by pulling it with both hands. A warning is included to discharge the high voltage from the FBT before removing the Anode Cap.
- Speaker Removal: Remove screws and press the tension rib.
- CRT Removal: Spread a soft mat on the floor, place the TV set face down, remove the 4 nuts mounting the CRT to the front cabinet, and lift the CRT. A caution is provided regarding handling the picture tube due to high vacuum and large surface area, emphasizing not to lift by the neck, scratch the picture tube, or apply excessive pressure.
Troubleshooting:
The manual includes flowcharts for troubleshooting common issues:
- No Video (Raster On, No Sound): Guides checking the IF Pin of Tuner, IC901 (Pin 37, 40), and then checking/replacing TU01, IC901, IC201.
- No Power: Guides checking the 125V, 13.0V B+ Lines, IC802 (Pin 9 (5V)), IC901 (Pin 16 (4V)), IC901 (Pin 18 - Stand-by 0V, Normal: 5V), IC201 (Pin 46 (H out)), and then checking/replacing IC801, D801, F802, IC802 (KA7630), IC901, IC201, D401, D402.
- No Video (Sound OK): Guides checking IC201 (Pin 12, 37 (8V)), IC201 (Pin 4 (V-FBS)), IC201 (Pins 19, 20, 21), IC201 (Pin 27 (Y-IN)), IC501 on the CRT PCB, and then checking/replacing IC802 KA7630, IC201, IC201, Q203, IC501, R417, R505 (HEATER 6.3Vrms), D503 (CRT G1 pin), CRT, V509.
- No Sound (Video OK): Guides checking IC201 (Pin 15 (Sound Out)), IC602 (Pins 7, 10 (10V)), IC602 (Pin 4 (B+ 10, 12.5V)), IC602, A/V Front assembly, and then checking/replacing IC201, Q903, Q907, R812, R813, IC602, IC901.
- No TTX: Guides checking IC901 (Pins 24), IC901 (Pin 31, 32, 33, 34, 35), IC201 (Pin 23, 24, 25, 26), and then checking/replacing Q702, IC901, IC901, IC201.
Alignment and Adjustments:
The manual details various alignment and adjustment procedures:
- Preadjustment: Factory mode adjustments for video mode, EEPROM (IC902) or CRT replacement.
- Main Adjustment Parameter: Table of OSD abbreviations, ranges, and initial data for various parameters.
- Test Pattern (Aging Mode): Instructions for accessing and using the aging mode for pre-heating the CRT.
- Option Bytes: Detailed tables for configuring option bytes for different regions (China, Singapore, Germany, United Kingdom, France/Switzerland, Eastern Europe, Russia/CIS, Australia, India, Middle East/Africa, Vietnam/Malaysia).
- Reset: Instructions for resetting channels, sort, system, timer, blue screen, child lock, picture, volume, and CH. Skip.
- Other Adjustments:
- General: Adjusting color TV needs, picture quality, specified test equipment, impedance matching, overload, and connecting TV to AC power source.
- Automatic Degaussing: Explains how the degaussing coil operates and how to manually degauss the TV.
- High Voltage Check: Instructions for checking and adjusting the B+ power supply and high voltage.
- Focus Adjustment: Input a black and white signal, adjust tuning control, and adjust FOCUS control.
- Cathode Voltage Adjustment (Screen Adjustment): Connect CRT socket pin GK to an oscilloscope probe, input a gray scale pattern, and use the P mode key to adjust screen VR.
- Purity Adjustment: Warm up the receiver, plug in the CRT deflection yoke, plug in the convergence yoke, input a black and white signal, fully demagnetize the receiver, turn the CONTRAST and BRIGHTNESS controls to maximum, loosen the clamp screw holding the yoke, slide the yoke backward or forward, tighten the convergence yoke, slowly move the deflection yoke forward, and temporarily tighten the deflection yoke. Produce blue and red rasters and adjust the low light controls.
- Convergence Adjustment: Warm up the receiver, adjust the two tabs of the 4 pole magnets, adjust the Brightness and Contrast controls, adjust the two-tab pairs of the 4 pole magnets, and repeat adjustments if necessary.
- VCO Adjustment: Set the VCO data to 80 (Factory Mode).
- RF AGC Adjustment: Set the AGC data to 14 (Factory Mode).
- Sub-Color Adjustment: Set SCR data to 10 (Factory Mode).
- Geometry Adjustment: Adjust PHS (using the width coil), SC (S-Correction), PVS (Vertical shift), PSL (Vertical-Slope), and PHS (Horizontal shift).
- White Balance Adjustment: Warm up the TV, input a Toshiba pattern, adjust SBT and SCR in Factory Service Mode for Low-Light and High-Light adjustments respectively.
Exploded View & Parts List:
The manual includes an exploded view diagram of the television and a detailed parts list, including code numbers, descriptions, specifications, and quantities for various components such as the cabinet, speaker, knob, clamp-wire, screw, CRT, and power cord.
Electrical Parts List:
A comprehensive list of electrical parts is provided, including capacitors, resistors, diodes, ICs, transistors, coils, transformers, tuners, switches, and other components, with their respective locations, code numbers, descriptions, specifications, and remarks.
Block Diagram:
A block diagram (8-1 S15A) illustrates the interconnections and signal flow between major components of the television, including the tuner, CD/CB/CK model delete, pre-amp, EEPROM, IC-MCU, STR, switching trans, power cord, diode bridge, sound amp, vertical amp, RGB amp, and CRT.
PCB Layout:
A detailed PCB layout diagram (9-1 PCB Main) shows the arrangement of components on the main printed circuit board, with component locations and coordinates.
Wiring Diagram:
A wiring diagram (10-1 S15A) illustrates the connections between the power cord, CRT PCB, and various connectors (CN501B, CN701, CN602) for signals like R-OUT, G-OUT, B-OUT, GND, H-OUT, V-OUT, HEAT, SOUND L/R OUT, FRONT VIDEO IN, 21PIN VIDEO IN, and FRONT AUDIO OUT.
Schematic Diagrams:
Detailed schematic diagrams are provided for various sections of the television:
- ONECHIP (11-1): Shows the internal circuitry and connections of the main one-chip IC, with power and signal lines highlighted.
- SOUND, EXT-A/V (Europe/Africa) (11-2): Details the sound and external A/V input/output circuitry for Europe/Africa models, including information bus details.
- SOUND, EXT-A/V (Middle East / Asia) (11-3): Details the sound and external A/V input/output circuitry for Middle East/Asia models, including information bus details.
- POWER / CRT / VERTICAL / HORIZONTAL (11-4): Shows the power supply, CRT drive, vertical, and horizontal deflection circuits, with warnings regarding servicing and critical components.
- MICOM (NON-TTX) (11-5): Details the microcontroller unit (MICOM) circuitry for non-Teletext models.
- MICOM (TTX) (11-6): Details the microcontroller unit (MICOM) circuitry for Teletext models.
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