Kenwood KR 8010 Service Manual

The Kenwood KR 8010 is a high-performance stereo receiver featuring 80 watts per channel RMS power output, quartz PLL synthesized tuning, 8 FM and 8 AM station presets, loudness control, tape monitoring, and multiple audio inputs/outputs. This service manual provides comprehensive technical information for service technicians, including schematics, alignment procedures, parts lists, and troubleshooting guidelines for proper maintenance and repair.

1. Technical Specifications 2. Block Diagram Overview 3. Circuit Descriptions 4. Alignment Procedures 5. Parts List 6. Schematic Diagrams 7. PCB Layouts 8. Service Adjustments 9. Troubleshooting Guide 10. Safety Precautions 11. Replacement Parts

Technical Specifications

Complete technical specifications and performance characteristics of the Kenwood KR 8010 stereo receiver.

Parameter	Specification
Power Output	80W + 80W RMS (8 ohms, 20Hz-20kHz)
THD	0.02% at rated output
Frequency Response	10Hz-50kHz (+0.5dB, -3dB)
Input Sensitivity	Phono: 2.5mV; Aux: 150mV
S/N Ratio	Phono: 76dB; Aux: 100dB
Tuning Range	FM: 87.5-108MHz; AM: 530-1620kHz
Preset Stations	8 FM, 8 AM
Power Requirements	120V AC, 60Hz, 380W
Dimensions	440W x 150H x 370D mm
Weight	12.5 kg

Block Diagram Overview

System block diagram showing signal flow and major circuit sections.

Tuner Section: FM front end, IF amplifiers, MPX decoder
Preamplifier: Phono equalizer, tone controls, selector switches
Power Amplifier: Driver stage, output transistors, protection circuit
Power Supply: Transformer, rectifiers, regulators
Control Section: Microprocessor, display drivers, function controls

WARNING! High voltages present in power supply section. Exercise extreme caution when servicing.

Circuit Descriptions

Detailed description of major circuit sections and their operation.

FM Tuner: RF amplifier, mixer, local oscillator, IF stages
Phono Equalizer: RIAA compensation, low-noise transistors
Tone Control: Bass and treble controls, loudness circuit
Power Amplifier: Complementary symmetry output, thermal protection
Power Supply: Dual secondary transformer, bridge rectifier

CAUTION! Static sensitive components. Use proper grounding when handling ICs and transistors.

Alignment Procedures

FM Tuner Alignment: Required test equipment: FM signal generator, oscilloscope, VTVM
IF Alignment: 10.7MHz IF stages adjustment procedure
MPX Alignment: Stereo decoder adjustment for minimum distortion
AM Tuner Alignment: RF and IF alignment steps
Power Amplifier Bias: DC offset and bias current adjustment
Protection Circuit: Overcurrent and thermal protection verification
Test Points: Voltage and waveform measurement points
Alignment Tools: Required alignment tools and test jigs

Parts List

Complete listing of all components with part numbers and specifications.

Semiconductors: Transistors, diodes, ICs with replacement cross-references

Resistors: Carbon film, metal film, power resistors with wattage ratings

Capacitors: Electrolytic, ceramic, film capacitors with voltage ratings

Transformers: Power transformer, output transformers specifications

Mechanical Parts: Switches, potentiometers, connectors, hardware

Schematic Diagrams

Complete schematic diagrams for all circuit sections.

Main Amplifier Section: Power amplifier and protection circuits
Tuner Section: FM and AM tuner circuits
Preamplifier: Phono and line stage circuits
Power Supply: Transformer, rectification, and regulation
Control Section: Microprocessor and display circuits

Tip: Use original schematics for accurate component values and circuit tracing.

PCB Layouts

Printed circuit board layouts and component placement diagrams.

Main Board: Component side and solder side views
Tuner Board: FM/AM tuner module layout
Front Panel: Control and display board
Power Supply: Power transformer and rectifier board
Heat Sink: Output transistors mounting details
Interconnections: Wiring diagrams between boards
Test Points: Location of critical test points
Grounding: Ground plane and star grounding points

WARNING! Observe proper insulation and clearance distances when replacing components.

Service Adjustments

Routine service adjustments and calibration procedures.

Troubleshooting Guide

Systematic troubleshooting procedures for common problems.

Symptom	Possible Cause	Corrective Action
No power	Fuse, power switch, transformer	Check main fuse; verify power switch operation; test transformer primary
No audio output	Protection circuit, output transistors	Check protection relay; test output transistors for shorts
Distorted audio	Bias current, driver transistors	Adjust bias current; check driver stage transistors
No FM reception	Tuner section, power supply	Verify tuner supply voltages; check local oscillator operation
Intermittent operation	Cold solder joints, connectors	Inspect for cracked solder joints; clean and reseat connectors

Reset: Power cycle unit to reset protection circuits.

Service: Authorized Kenwood service centers only for warranty repairs.

Safety Precautions

Essential safety procedures for service technicians.

CAUTION! Always disconnect power before servicing. Use isolation transformer when working on live circuits.

Replacement Parts

Authorized replacement parts and cross-reference information.

Kenwood part numbers with manufacturer equivalents. For genuine Kenwood parts, contact authorized parts distributors. Copyright © 1980-1982 Kenwood Corporation; all rights reserved. For technical support, contact Kenwood service department or visit www.kenwood.com.