Cambridgeaudio 640 a service manual

This is the 41 pages manual for cambridgeaudio 640 a service manual.
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cambridgeaudio 640 a service manual

Extracted text from cambridgeaudio 640 a service manual (Ocr-read)


Page 1

640A SERVICE MANUAL TABLE OF CONTENTS Safety Precautions & Important Notes 3 Amplifier Bias Set-up 4 Main Assembly BOM (Silver Unit) 5 – 7 Input & Tone PCB Schematic (Tone Control) 8 Revised: Input & Tone PCB Schematic (Input Select) 9 Input & Tone PCB Layout (Top Side) 10 Input & Tone PCB Layout (Bottom Side) 11 Input & Tone PCB BOM 12 Front Panel Schematics 13 Front Panel PCB Layout (Top Side) 14 Front Panel PCB Layout (Bottom Side) 15 Front Panel PCB BOM 16 Power Amp Schematic (Power Supply) 17 Power Amp Schematic (Protection) 18 Power Amp Schematic (Left Channel) 19 Power Amp Schematic (Right Channel) 20 Power Amp PCB Layout (Top Side) 21 Power Amp PCB Layout (Bottom Side) 22 Power Amp PCB BOM 23 – 25 Speaker Output Schematic 26 Speaker Output PCB Layout (Top Side) 27 Speaker Output PCB Layout (Bottom Side) 28 Speaker Output PCB BOM 29 Mains Input Schematic 30 Mains Input PCB Layout (Top Side) 31 Mains Input PCB Layout (Bottom Side) 32 Mains Input PCB BOM 33 IC Pin Layout Details 34 – 38 Silver / Black Difference BOM 39 Amended Input Circuit Schematic (Jan 2004) 40 Amended Input Circuit Schematic (March 2005) 41

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SA FE TY P R EC AU TIO NS & I M PO RTA N T N OTES 1. Check that the rear of the product indicates the correct supply voltage \ for you area. 2. The lighting flash with the arrowhead within an equilateral triangle is intended to alert the user or service agent to the presence of dangerous voltages within the product enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. 3. The exclamation point within an equilateral triangle is intended to alert the user or service agent to the presence of important operating and maintenance (Servicing) instructions in the literature accompanying the appliance. 4. This product complies with EEC Low Voltage (73/23/EEC) and Electromagnetic Compatibility (89/336/EEC) Directives when used and serviced in accordance with this manual. For continued compliance all components marked safety and EMC critical must only be replaced by Cambridge Audio approved parts. 5. Any unauthorised design alterations or additions will void the manufacturers warranty; furthermore the manufacturer cannot accept responsibility for personal injury or property damage resulting therefrom. 6. When servicing, care should be taken to observe the original routing \ and dressing of the leads and it should be confirmed that they have been\ returned to normal after re-assembly. Notes on chip component replacement Never reuse a component that has been removed from a PCB Notice that the minus side of a tantalum capacitor may be damaged by hea\ t C O PY RIG HT N OTIC E. © 2005 Audio Partnership PLC. All rights reserved. Cambridge Audio and Azur are registered trademarks of Audio Partnership \ PLC. This document may not be reproduced, distributed, transmitted, displayed, published, or broadcast without the express written prior permission of Audio Partnership PLC. Alteration or removal of any trademark, copyright, or other notice from this content is prohibited. Information provided in this document is provided solely for the use of official service agents in repairing and servicing Audio Partnership PLC products.