RCA ATC221 free download

File name RCA Chassis ATC221 (Schematic).pdf

VERTICAL TO E8 RED BIAS <21-B> TP50 TO E7 GRN BIAS E5003 E5007 RED OUTPUT 194V FOREWORD This publication is intended to aid the technician in servicing the ATC221 television chassis. Directed at the safety circuitry, it will explain the theory of operation of those circuits highlighting new and different technologies associated with this digitally controlled chassis. It is designed to assist the technician to become more familiar with the safety circuit operation, increase confidence and improve overall efficiency in servicing the product. Note: This publication is intended to be used only as a training aid. It is not meant to replace service data. Thomson Service Data for these instruments contains specific information about parts, safety and alignment procedures and must be consulted before performing any service. The information in this manual is as accurate as possible at the time of publication. Circuit designs and drawings are subject to change without notice. SAFETY INFORMATION CAUTION Safety information is contained in the appropriate Thomson Service Data. All product safety requirements must be complied with prior to returning the instrument to the consumer. Servicers who defeat safety features or fail to perform safety checks may be liable for any resulting damages and may expose themselves and others to possible injury. All integrated circuits, all surface mounted devices, and many other semiconductors are electrostatically sensitive and therefore require special handling techniques. First Edition 0431 - First Printing Copyright 2004 Thomson, Inc. Trademark(s)® Registered Marca(s) Registrada(s) Printed in U.S.A. Prepared by Thomson, Inc. Technical Training Department PO Box 1976 Indianapolis, Indiana 46206 U.S.A. ATC221 Safety Shutdown 2 ATC221 Shutdown Circuits This training material assumes a knowledge of the current Thomson television chassis ATC221. The material has been prepared using general values of components. Components and other circuitry may change over time so in all cases Electronic Service Data for the instrument should be consulted for the most accurate component values and voltages. Typical Thomson nomenclature for component ID and references to ground and supply voltages will be used throughout. To designate individual pin assignments of an IC and active components the following formats are used. IR001-115 designates IC IR001, pin 115. TR198-B designates the Base of transistor TR198. Power supply labels will be used whenever possible. S for standby operation and R for run. Normal operating voltages and signal designations will be used. For example: SAFETY ENABLE would stand for a signal that under normal run conditions would be a logic HIGH, in most cases near +5V. SAFETY ENABLE would signify a signal whose normal operating level is LOW, in most cases near ground. ATC221 Safety Shutdown 3 AUDIO Shutdown/Safety Block Outline BEAM CURRENT IV200 VID PROC PS LOSS 4 EHTIN RUN:<+3V XRP XRP: >+3.8V RP