Denon UCD-250 Service Manual

D F N © N Hi-Fi Personal Component System
SERVICE MANUAL
PERSONAL COMPONENT SYSTEM
UNIT No. UCD-250
MAIN FEATURES
@ AM/FM 30-station random preset tuner
Random presetting permits easy operation and will be convenient for
the increased number of FM stations in the future.
@ Independent power amplifier designed for quality sound
High quality 50 W per channel power amplifier with large speaker
terminals.
@ New SDB control
The Super Dynamic Bass control circuit delivers clear bass sound.
@ Super linear converter and high performance digital filter
Denon’s unique systems for preventing loss of CD sound quality
permit excellent sound field reproduction.
BEFORE USING
@ Moving the system
To prevent short-circuiting or damage of connection cords, be sure to
unplug the power cord and disconnect all connection cords before
Moving the system.
In addition, always remove CDs before moving the system. if not, the
CD may be scratched.
@ Before turning the power on
Check again that all connections are proper and that the connection
cords are not damaged. Always set the power switch to the STANDBY
position before disconnecting connection cords.
(Compact Disc Player)
COMPACT
DIGITAL AUDIO
@ The D-250 Persona! Component System consists
of the following:
Power Amplifier
MW, LW, FM Tuner /
Pre Amplifier Section
Remote Control Unit
Cassette Deck Section
CD player Section
Editing circuit
Automatic selection of CD tracks for minimum blank space on the tape
when recording.
Dolby B, C and HX PRO circuits
For high quality sound in playback and recording.
CD SRS circuit
CDs can be recorded at the touch of a button.
Easy-to-use remote control unit
Auto on/off function
This function switches on the power with just a press of the CD or
cassette deck play button. The power is switched off about 10 minutes
after playback has finished.
Humming may be produced if the system is set near a TV set or other
audio component or its connection cords. If this happens, try
changing the position of the equipment and connection cords.
Do not move the system abruptly from a cold place to a warm place,
as this may cause dew (water droplets) to form in the set, preventing
proper operation. if this happens, wait one hour before using the
system.
Be sure to keep this manual
The illustrations used in this manual may differ from the actual
system.
Check that the following parts are included in the package aside from the main unit:
@® Operating Instructions .....
@ FM Antenna
@® AM Loop Antenna
® Remote Controller
© R6P/AA batteries
© System Connectors1&2_ ...
@ FM Antenna adaptor ...
Pin Plug Cords
PENN = =
NIPPON COLUMBIA CO. LTD.

Denon UCD-250 Specifications

General

Brand	Denon
Model	UCD-250
Category	Stereo System
Language	English

Summary

MAIN FEATURES

Main Features Description

Highlights key features of the UCD-250 Compact Disc Player, including tuner, amplifier, and sound quality.

BEFORE USING

Pre-Operation Guidelines

Provides essential precautions and instructions before operating the system for the first time.

SYSTEM SPECIFICATIONS

Technical Specifications

Detailed technical specifications for each component of the D-250 system: tuner, amplifier, CD player, cassette deck.

IMPORTANT SAFETY INFORMATION

Safety Warnings and Precautions

Crucial safety warnings to prevent fire or shock hazards, including electrical safety and handling.

Handling and Environmental Notes

Guidelines on avoiding high temperatures, moisture, foreign objects, and proper cord handling for safe operation.

ANTENNA CONNECTIONS

Connecting Antennas

Instructions for connecting the supplied AM loop and FM antennas to the system for optimal reception.

Outdoor Antenna Installation

Guidance on installing and connecting an outdoor antenna for improved radio reception, including placement tips.

PART NAMES AND FUNCTIONS

Amplifier and Tuner Controls

Identification and function of controls on the power amplifier and tuner-pre-amplifier sections.

USING THE TIMER

Timer Setting Procedure

Instructions for setting the timer to automatically turn the system on or off at a specified time.

Current Time Setting

Guide on how to set the 24-hour clock display, essential for timer functions.

CASSETTE DECK FUNCTIONS

Auto Reverse and Tape Types

RECORDING CASSETTE TAPES

Music Search and Display

SYNCHRO DUBBING AND CD PLAY

Synchro Dubbing Procedure

CD PLAY FUNCTIONS

Regular CD Playback Steps

CD PLAYBACK NAVIGATION

Track Navigation Methods

EDITED RECORDING ON TAPE

Edited Recording Process

How to perform edited recording of CDs onto cassette tapes, dividing tracks between sides A and B.

Programmed Edited Recording

REMOTE CONTROL UNIT OPERATION

Remote Control Usage and Batteries

Guidelines for using the remote control unit, including cautions and how to insert batteries.

Remote Control Button Functions

AUTO ON/OFF FUNCTION

Auto On/Off Feature Explanation

TROUBLESHOOTING GUIDE

General Troubleshooting Steps

A comprehensive table listing common symptoms, their causes, and solutions for the entire system.

CD Player Troubleshooting

DISASSEMBLY PROCEDURES

Removing Outer Covers

Step-by-step guide for removing the outer covers and front panel of the CD player unit.

Removing Internal Boards

Instructions for removing internal circuit boards, including the LCD tact switch unit.

Removing CD Mechanism Unit

Procedure for safely removing the CD mechanism unit from the main chassis.

UNIT MECHANISM SERVICING

Servicing Precautions

Critical precautions for servicing, especially regarding the semiconductor laser (LD) and handling.

LASER CIRCUIT HANDLING

Laser Control Circuit Precautions

Important precautions when handling the laser control circuit, including sensitivity to temperature and light output.

Wiring and Handling Guidelines

Guidance on proper wiring, avoiding digital noise, and general handling precautions for the CD mechanism.

Semiconductor Laser Safety

Critical instructions for protecting eyes from the laser and preventing destruction by surge currents or static electricity.

SERVICE POINTS - TRAY MECHANISM

Tray Mechanism Parts Replacement

Detailed steps for replacing parts of the CD player's tray mechanism, including the disc holder and latches.

UNIT MECHANISM SERVICE PROCEDURES

Unit Mechanism Removal and Servicing

Lens and Laser Inspection

ADJUSTMENT METHOD

Service Program Operation

How to start and operate the service program for making adjustments using the unit's buttons.

Adjustment Instruments and Preparation

Lists instruments needed for adjustment and preparation steps, including setting controls.

OFFSET ADJUSTMENT PROCEDURES

Tracking Offset Adjustment

Detailed procedure for adjusting the tracking offset using an oscilloscope and VR501 control.

Focus Offset Adjustment

Step-by-step guide for adjusting the focus offset using an oscilloscope and VR502 control.

INTEGRATED CIRCUIT (IC) FUNCTIONS

IC Pin Functions Overview

MICROPROCESSOR PERIPHERAL WIRING

CXD2500AQFP (IC681) Pin Functions

MICROPROCESSOR PIN DESCRIPTIONS

μPD75517GF (IC682) Pin Functions

MICROPROCESSOR WIRING DIAGRAM

Peripheral Wiring Diagram

CD MECHANISM PARTS LIST

CD Mechanism Component Breakdown