To Next PageTo Next Page
Need help?Do you have a question about the JVC AV-20320/S and is the answer not in the manual?
This document provides service information for the JVC AV-20320/S and AV-20321/S color televisions, including specifications, features, adjustment procedures, and parts lists.
The JVC AV-20320/S and AV-20321/S are color televisions designed with a new chassis for simplified circuitry, utilizing a single board. They are equipped with a miniature tuner for both TV and CATV reception. The televisions feature a multifunctional remote control that allows for picture adjustment. A notable usage feature is the "CHANNEL GUARD" function, which prevents the selection of specific channels unless a designated "ID number" is entered. The internal control system relies on I2C bus control, implemented with single-chip ICs.
Key usage features include the "VIDEO STATUS" function, "ON/OFF TIMER" function, and "HYPER SURROUND" function for enhanced audio. The televisions are fitted with a common 75Ω V/U (F-Type) ANT Terminal for antenna connection. A "SLEEP TIMER" allows for real-time setting of a sleep duration. Closed-caption broadcasts can be viewed, and the units include an Audio Video input terminal and a Variable Audio output terminal. An integrated MTS (Multi-Channel Television Sound) system is also built-in.
The manual outlines several maintenance and adjustment procedures.
The document emphasizes safety during service, including the use of specified replacement parts, proper handling of components, and adherence to safety checks like isolation transformer usage, dielectric strength tests, and leakage current measurements. It highlights the importance of using an isolation transformer when the chassis is hot and connected to the AC power line. It also details procedures for checking the live side and isolated neutral side of the power circuit.
Instructions are provided for removing the rear cover, main PW board, and speaker. This includes specific screw locations and cautions for handling components.
This model uses a memory IC that stores data for proper operation of video and deflection circuits. The replacement procedure involves:
Detailed instructions are given for replacing chip components, including cautions for soldering (avoiding overheating, using appropriate solder, and not reusing chip parts) and specific steps for removing and installing resistors, capacitors, transistors, and diodes using tweezers and soldering irons.
A comprehensive section covers various adjustments, including:
A procedure is outlined to check the high voltage hold down circuit by setting a resistor between connector X and terminals 1 & 3, and observing if the screen disappears.
The model includes self-check functions that detect malfunctions and indicate them via LED flashes. Details of detection, method of detection, and state of malfunction are provided for CRT NECK protector and high voltage transformer output. The self-check function begins about 5 seconds after power-on. In case of malfunction, the power is cut off immediately, and the ON-TIMER LED flashes at 0.5-second intervals.
The document includes detailed parts lists for the AV-20320/S (Charcoal Model) and AV-20321/S (White Model), covering main PWB components, remote control unit parts, and packing materials. Abbreviations for resistors, capacitors, and tolerances are also provided.
General
