This document is a service manual for Sony Trinitron Color Video TVs, specifically models within the BC-4A chassis series. It covers the KV-VF21M40, KV-VF21M70, and KV-VF21M77 models. The manual provides detailed information for servicing and maintaining these television sets, including specifications, circuit diagrams, and component lists.
Function Description:
The Sony Trinitron Color Video TVs are designed for home entertainment, offering both television reception and video playback capabilities. The KV-VF21M77 model, in particular, includes G-CODE functionality for simplified VCR programming. These TVs are equipped with a Trinitron picture tube, known for its high-quality image display. The integrated VHS standard video section allows for recording and playback of VHS tapes, making them versatile entertainment hubs. The audio recording system is monaural, supporting PAL/MESECAM and NTSC formats. The TVs also feature various input and output options for connecting external devices.
Important Technical Specifications:
TV Section:
- Television System: B/G, I, D/K, M
- Color System: PAL/SECAM and NTSC3.58/NTSC4.43
- Bilingual System (VF21M77 ONLY): NICAM bilingual I
- Channel Coverage: Detailed in "Receivable channels and channel display" section (not fully detailed in provided excerpt).
- Picture Tube: Trinitron, 21 inches (approx. 50.7 cm measured diagonally).
- Antenna In: 75-ohm antenna socket for VHF/UHF.
Video Section:
- Format: VHS standard
- Video Recording System: Rotary 2-head helical scanning system
- Audio Recording System: Monaural
- Video Signal: PAL/MESECAM/NTSC
- Tape Speed (PAL/MESECAM): SP: 23.39 mm/sec., LP: 11.70 mm/sec.
- Tape Speed (NTSC): SP: 33.35 mm/sec., EP: 11.11 mm/sec.
- Maximum Recording Time (PAL/MESECAM): SP: 240 minutes with E-240, LP: 480 minutes with E-240.
- Maximum Recording Time (NTSC): SP: 180 minutes with T-180, EP: 540 minutes with T-180.
- Inputs (1, 2/GAME IN):
- Video: Phono jack, 1 Vp-p, 75 ohms, unbalanced, sync negative.
- Audio: Phono jack, input level: 500 mVrms.
- Headphones Jack: Minijack.
General:
- Clock: Quartz locked.
- Power Requirements: 110-240 V AC, 50/60Hz.
- Power Consumption: 123 W.
- Operating Temperature: 5° C to 40° C (41° F to 104° F).
- Storage Temperature: -20° C to 60° C (-4° F to 140° F).
- Dimensions: 489 x 500 x 485 mm (19 3/8 x 19 3/4 x 19 1/8 inches).
- Mass: 27.5 kg (60 lb 10 oz.).
Usage Features:
The TVs are designed for ease of use, featuring a remote control for convenient operation. The G-CODE feature on the KV-VF21M77 simplifies the programming of video recordings. The bilingual system (NICAM I) on the VF21M77 model enhances the viewing experience by offering multiple language options for audio broadcasts. The inclusion of a VHS recorder allows users to watch and record their favorite programs directly on the television set. Inputs for external devices like game consoles (GAME IN) expand the entertainment possibilities. The Trinitron picture tube ensures a clear and vibrant display for all content.
Maintenance Features:
This service manual is primarily intended for technicians and provides comprehensive information for maintenance and repair.
- Detailed Circuit Diagrams: The manual includes schematic diagrams for various boards, such as the A board, CV board, F board, and MA10 board (divided into 1/3, 2/3, and 3/3 sections), which are crucial for troubleshooting and component replacement.
- Waveforms: Specific waveforms at various test points are provided for different operating modes (e.g., PAL/SECAM, NTSC, REC, PB), aiding in diagnosing signal integrity issues.
- Component Lists: Mark lists for specific ICs and components on different boards (e.g., A BOARD mark LIST, MA10 BOARD mark LIST) help identify correct parts for replacement.
- Semiconductor Information: A dedicated section details various semiconductors used in the TV, including their package types and pin configurations, which is essential for component-level repair.
- Safety Warnings: The manual includes important safety notes, such as a warning about high voltage (up to 600 Vp-p) in certain circuits (e.g., F board), emphasizing the need for caution during inspection and repair to prevent electric shock.
- Microfilm Reference: The "MICROFILM" note with a page number (21) suggests that certain detailed information or diagrams might be available on microfilm, indicating a structured approach to documentation for service personnel.
- Supplied Accessories: The list of supplied accessories (remote control, batteries, stabilizer band, clamps, wood screws, AC plug adaptor) indicates typical items that might need replacement or adjustment during service.
- Model-Specific Information: The manual differentiates between models (e.g., KV-VF21M77 vs. KV-VF21M40/M70) for certain components, ensuring that the correct parts are used for each specific variant.
- Chassis Number Reference: The chassis number (BC-4A) and specific SCC-Pxx-A numbers for different models and destinations (E, ME, JE, HK) are provided, which is vital for ordering correct replacement parts and ensuring compatibility.
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