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Hi-Fi Products
CSA-13
Service Bulletin
Sony Service Company - Technical Services A Division of Sony Electronics Inc. Sony Drive, Park Ridge, New Jersey 07656
Model:
STRD311
No.
436
Subject: Output Transistor Failure Symptom: (11)
Date: May 1, 1995
Output Transistors fail, sometimes repeatedly, after replacement.
Solution:
After replacing the defective output transistors, and any other defective components, change the value of the resistors as noted below. REF FORMER DESCRIPTION R707 R757 3.3K OHM 1/4 WATT 3.3K OHM 1/4 WATT PART NUMBER 1-249-423-11 1-249-423-11 NEW DESCRIPTION 15K OHM 1/4 WATT 15K OHM 1/4 WATT PART NUMBER 1-249-431-11 1-240-431-11
Note: When replacing output transistors be sure to use a sufficient amount of heat sink compound on the replacement device. Tighten the mounting screw with enough force to firmly secure the transistor to the heat sink for adequate heat transfer. In some instances the following 47uf 25V electrolytic capacitors, C709, 759, 704, and 754 were not mounted on the main board at the factory. Add these capacitors, part number 1-124-477-11, before releasing the unit.
Reference: FPR-P Autoflagged - YES
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Filename: HFP0436.SB Directory: J:\SBDOC\MAY95 Template: C:\WINWORD\S_BULL.DOT Title: STRD311 Service Bulletin Subject: Output Modification Author: Hoyt Wing Lee Keywords: Comments: Creation Date: 05/01/95 11:13 AM Revision Number: 2 Last Saved On: 05/01/95 11:13 AM Last Saved By: Hoyt Wing Lee Total Editing Time: 0 Minutes Last Printed On: 04/01/96 9:41 AM As of Last Complete Printing Number of Pages: 1 Number of Words: 203 (approx.) Number of Characters: 1,158 (approx.)