This document is a service manual for Panasonic Color Televisions, specifically models CT-27SL13MG, CT-27SL13MUG, CT-27SL33MG, CT-27SL33MUG, CT-27SL13G, CT-27SL13UG, CT-27SL33G, CT-27SL33UG, CT-27C8G, CT-27G8G, CT-27G8UG, CT-27L8G, CT-27L8UG, and CT-27L8SG. It provides comprehensive information for servicing and maintaining these television sets.
Function Description:
These devices are color televisions designed for home entertainment. They feature a 128K micro-controller, support English, Spanish, and French menu languages, and include closed captioning and V-Chip (USA/Canada) functionalities. The televisions have 181 channels, and some models (CT-27SL33MG/MUG, CT-27SL33G/UG) offer PIP (Picture-In-Picture) with 2T PIP and 2T SPLIT capabilities, while others (CT-27SL13MG/MUG, CT-27SL13G/UG) do not. All models include a channel info banner and video input skip. They support 75 Ohm input and come with remote controls (EUR7613Z60 or EUR7713Z70 for SL13/SL33 models, EUR7613Z10 or EUR7713010 for C8G/G8G/L8G models). The CRT supplier is MDDA (FLAT) for SL13/SL33 models and SAMSUNG (FLAT) for C8G/G8G/L8G models. All models feature a 3-digit comb filter, HEC/VEC (X=BOTH), VM, V/A NORM (X=BOTH), color temp, preset/input labeling, and video input picture memory. They support MTS/SAP/DBX, have a built-in audio power of 5Wx2 with 2 speakers, and include bass/balance/treble control, AI sound, and surround sound. Spatializer/BBE is also supported. Connectivity options include 3 (2/1) A/V inputs (rear/front), F, V audio outputs, and 1 component input (Y, Pb, Pr). S-Video input (rear/front) is available as 1/0. Video input jack is 1Vp-p 75 Ohm phono jack, and audio input jack is 500mV RMS 47k Ohm. Some models also include a headphone jack.
Important Technical Specifications:
- Micro-controller: 128K
- Channel Count: 181
- Audio Power: 5Wx2
- Speakers: 2
- Video Input Jack: 1Vp-p 75 Ohm, phono jack
- Audio Input Jack: 500mV RMS 47k Ohm
- Dimensions (WxDxH):
- CT-27SL13MG/MUG, CT-27SL13G/UG: 754.3x534.3x601.6mm (29.69x21.03x23.68in)
- CT-27SL33MG/MUG, CT-27SL33G/UG, CT-27C8G, CT-27G8G/UG, CT-27L8G/UG/SG: 665.2x544.5x594.8mm (26.18x21.43x23.41in)
- Weight (Kg/Lbs):
- CT-27SL13MG/MUG, CT-27SL13G/UG: 35.4/78.04
- CT-27SL33MG/MUG, CT-27SL33G/UG, CT-27C8G, CT-27G8G/UG, CT-27L8G/UG/SG: 34.5/76.05
- High Voltage (EHT): 30.55 ± 1.25kV (for MDDA CRT), 29.25 ± 1.25kV (for SAMSUNG CRT)
- B+ Voltage: 131.0V ± 2.0V
- Heater Voltage: 6.0 ± 0.24V (MDDA CRT), 6.3 ± 0.24V (SAMSUNG CRT)
- Insulation Test Current: 0.5mA ~ 2.0mA (at 1080VAC/60Hz for 1 second)
- Leakage Current (Cold Check): 240k Ohm to 5.2M Ohm (between jumpered AC plug and exposed metallic parts with return path to chassis), infinite (without return path).
- Leakage Current (Hot Check): AC potential not exceeding 0.75 volt RMS (or 0.5 milliamp for leakage current tester).
- Pb-free Solder Melting Point: 50 ~ 70 °F (30 ~ 40 °C) higher than standard solder, typically 700 ± 20 °F (370 ± 10 °C).
Usage Features:
The televisions offer a user-friendly interface with multi-language menus. The remote control provides access to various functions including power, volume, channel selection, mute, TV/Video input, menu navigation, numeric keypad, R-Tune, SAP, recall, sleep timer, and component input. Front controls are also available behind a door, including power, volume, channel, action, and TV/Video input.
Maintenance Features:
The service manual provides detailed instructions for various maintenance and adjustment procedures:
- Safety Precautions: Emphasizes the use of an isolation transformer, proper lead dress, replacement of damaged parts with manufacturer-recommended ratings, and careful handling of the picture tube to prevent implosion and X-ray radiation exposure.
- Leakage Current Checks: Detailed procedures for cold and hot leakage current checks to ensure electrical safety.
- Insulation Test: Procedure for checking insulation between exposed metallic parts and the AC line.
- X-Ray Radiation Check: Instructions for measuring high voltage and ensuring it is within tolerance to prevent X-ray radiation hazards.
- Horizontal Oscillator Disable Circuit Test: A final check to be performed before returning the receiver to the customer.
- Service Notes: Guidelines for handling components, especially those affixed with glue, and specific instructions for replacing leadless chip components (surface mount) and flat ICs, including soldering techniques and precautions against stress fractures.
- EEPROM Replacement: Step-by-step guide for replacing the EEPROM integrated circuit, including entering service mode, setting ID switch registers (ID1, ID2, ID3) according to the service adjustment table, and performing remaining adjustments.
- Lead-Free Solder (PbF) Information: Explains the use of lead-free solder in manufacturing, its higher melting point, and precautions for soldering (e.g., using a high-temperature iron, avoiding splashing, checking for excess solder on double-layered boards).
- Disassembly for Service: Instructions for removing the back cover, chassis (A-Board), C-Board (CRT output), and Y-Board (second tuner board).
- CRT Replacement: Detailed procedure for replacing the CRT, including discharging, removing components from the neck, noting hardware order, removing the degaussing coil and dag ground braid, and reinstallation.
- Chassis Service Adjustment Procedures:
- B+ Voltage Check: Procedure for checking B+ voltage (131.0V ± 2.0V) to the horizontal output and flyback circuits.
- High Voltage Check: Procedure for confirming high voltage (30.55 ± 1.25kV or 29.25 ± 1.25kV) is within tolerance.
- Service Mode (Electronic Adjustments): Instructions for entering and exiting service mode using the remote control, including toggling between aging and service modes.
- Service Adjustment Default Values: A table listing default register values for various items like MTS input level, color, tint, brightness, contrast, cut-off values, drive values, horizontal/vertical position, size, and ID switches.
- Sub-Brightness and Contrast / Service DAC Adjustment (BRIGH, CONT): Procedure for adjusting brightness and contrast using an oscilloscope connected to TP35.
- PIP Sub-contrast (PCONT): Procedure for adjusting PIP level.
- Color Output Adjustment / Service DAC Adjustment (COLOR, TINT, B-Y_G): Procedures for adjusting color and tint using a rainbow color bar pattern and an oscilloscope connected to TP37 and TP35.
- Color Temperature Adjustment / (B/W Tracking) / Service DAC Adjust. / (CUT R) (CUT G) (CUT B) (R DR) (B DR): Procedures for adjusting gray scale and warm whites in low and high light areas.
- Deflection Adjustments (H-Center, Vertical Linearity, V-Size, V-Position, V-S Correction): Procedures for adjusting horizontal and vertical geometry using a crosshatch or monoscope pattern.
- MTS Circuit Adjustments (Input Level, Stereo Separation): Procedures for adjusting MTS input level and stereo separation using an RMS meter and a scope.
- Clock Adjustment (CLOCK): Procedure for calculating and setting the clock adjustment DAC using a frequency counter.
- Parts Location and Lists: Diagrams and tables identifying main components on the A-Board, C-Board, and Y-Board, along with detailed parts lists including capacitors, diodes, fuses, integrated circuits, coils, transistors, relays, resistors, transformers, crystals/filters, and other accessories.
The manual emphasizes the importance of using accurate, calibrated high voltage meters and following all safety precautions during servicing. It also notes that specifications are subject to change without notice.
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