Denon AVR-685

SERVICE MANUAL
MODEL AVR-1705/685
AV SURROUND RECEIVER/AMPLIFIER
For U.S.A., Canada, Europe,
China & Taiwan R.O.C. model
16-11, YUSHIMA 3-CHOME, BUNKYO-KU, TOKYO 113-0034 JAPAN
X0202 V.01 DE/CDM 0406
Some illustrations using in this service manual are
slightly different from the actual set.
●
Please use this service manual with referring to the
operating instructions without fail.
●
For purposes of improvement, specifications and
design are subject to change without notice.
●
●
本文中に使用しているイラストは、説明の都合上現物
と多少異なる場合があります。
●
修理の際は、必ず取扱説明書を参照の上、作業を行っ
てください。
サービスをおこなう前に、このサービスマニュアルを
必ずお読みください。本機は、火災、感電、けがなど
に対する安全性を確保するために、さまざまな配慮を
おこなっており、また法的には「電気用品安全法」に
もとづき、所定の許可を得て製造されております。
従ってサービスをおこなう際は、これらの安全性が維
持されるよう、このサービスマニュアルに記載されて
いる注意事項を必ずお守りください。
●
本機の仕様は性能改良のため、予告なく変更すること
があります。
●
補修用性能部品の保有期間は、製造打切後8年です。
注 意
Ver. 1

Denon AVR-685 Specifications

General

Channels	5.1
Frequency Response	20 Hz - 20 kHz
Total Harmonic Distortion (THD)	0.08 %
Input Sensitivity	200 mV
Signal-to-Noise Ratio	98 dB
Input sensitivity (MM)	2.5 mV
Signal to noise ratio (MM)	74 dB
Signal to noise ratio (line)	98 dB
Tuning range	FM

Summary

Safety Precautions

General Servicing Notes

Read manual, follow precautions, be aware of electrical hazards, use specified parts.

Leakage Current & Shock Prevention

Perform leakage checks, use insulation, reassemble correctly, and conduct post-service safety checks.

Unit Dimensions

Service Caution: Initialization

AV Receiver Initialization Procedure

Steps to initialize the AV receiver after component replacement.

Adjustments

Audio Section: Idling Current

Procedure for adjusting the idling current for the audio section.

Video Section: Component Video Level Adjustment

Procedure for adjusting component video signal levels.

Technical Diagrams

Block Diagram

Overview of the unit's internal functional blocks and connections.

Level Diagrams

Signal level diagrams illustrating signal flow and attenuation.

Component Identification: IC Pin Functions

Key IC Pinouts

Details pin functions for major ICs like CXP740096, ADSP-21266, LC89057W, BD3811K1, AD1837.

Additional IC Pinouts

Pinout details for various other ICs listed on pages 19-21.

FL Display Information

16-ST-66 GNK (FL301) Details

Specifications, pin assignments, and anode/grid connections for the FL display module.

Printed Wiring Board (PWB) Layouts

Main, CPU, Front, and Power Switch Boards

Component layouts for Main, CPU, Front, and Power Switch boards.

CNT, Video, Pre-Amp, Input-Vol, DSP Boards

Component layouts for CNT, Video, Pre-Amp, Input-Vol, and DSP boards.

Parts Information

Parts List Notes and Conventions

Explains symbols for parts, value notations, and dielectric strength.

Main P.W.B. Unit Components

Lists semiconductors, resistors, capacitors for the main PWB unit.

Exploded View and Packing Lists

Visual exploded view and packing lists with part identification.

Wiring Diagram

Schematic Diagram Notes

Schematic Conventions and Notices

Notes on symbols, value notations, voltage measurements, and diagram updates.

Schematic Diagrams

InputVolume and DSP Unit Schematics

Circuit diagrams for Input/Volume and DSP units.

Main and SB-AMP Unit Schematics

Circuit diagrams for Main and SB-AMP units.

Video, C-S Video, and Front Board Schematics

Circuit diagrams for Video, C-S Video, and Front boards.