Denon DCD-485 User manual

B
SERVICE MANUAL
Some illustration using in this service manual is slightly from the actual set.
MODEL
DCD-485/685
STEREO CD PLAYER
DCD-485
DCD-685
Hi-Fi Component

2
SAFETY PRECAUTIONS
SPECIFICATIONS
SAFETY PRECAUTIONS
The following check should be performed for the continued prtection of the customer and service
technician.
LEAKAGE CURRENT CHECK
Before reterning the unit to the customer,make sure you make either (1) a
leakage current check or (2) a line to chassis resistance check. If the leakage current exceeds 0.5
miliamps, or if hte resistance from chassis to either side of the power cord is less than 460 kohms,
the unit is detective.
AUDIO
DCD-485
DISCS
REMOTE CONTROL UNIT
FUNCTIONS AND DISPLAY
GENERAL CHARACTERISTICS
434 (W) x 100 (H) x 285 (D) mm
2 channels
Dimensions:
54.5 (W) x 140 (H) x 24.8 (D) mmExternal Dimensions:
Number of Channels:
Automatic searchi, programmed playback, repeat playback, manual search, auto space,
time mode, auto edit, dimmer, random playback, pitch control (DCD-685 only)
Functions:
Remote Control System:
Track number, time, music calendar and engaged modesDisplay:
Headphones jack
Infrared pulse system
RC-266
Others:
Mass: 3.4 kg
Mass: 85 g including batteries
AC 230 V, 50 HzPower Supply:
3V DC; two R6P (standard size AA) dry cell batteriesPower Supply:
Power consumption: 11 W
2 to 20 kHz
Freqency Responese:
0.2 to 2.0 V
Output Voltage:
98 dB
105 dB
Dynamic Range:
Signal to Noise ratio:
0.003 % (1 kHz)
Harmonic distortion:
102 dB (1 kHz)
Separation:
Below measurable limit:
Compact Disc format
( 0.001

% W. peak)
3.6 kg
12 W
100 dB
110 dB
103 dB (1 kHz)
Wow and Flutter:
✽Specifications and design are subject to change without notice for purpose of improvement.
SPECIFICATIONS
DCD-685

3
DISASSENBLY
Follow the procedure below in reverse order when reassembling
(Follow the procedure below in reverse order when reassembling)
1. Top Cover
1. Remove 4 screws
1
on both sides.
2. Remove 2 screws
2
on the Rear Panel.
3. Detach the Top Cover as shown in the fig.
2. Front Panel
1. Remove 1 screw
3
on the Rear Panel and
1 screw
4
fixing Support Bracket (b).
(only DCD-485)
2. Take off the Mecha Cover after removing
2 screws
5
.
Open the Tray by turning the Gear (a) clockwise,
then detach the Loader Panel.
3. Remove 3 screws
6
on the bottom edge of the
Front Panel.
4. Remove 2 screws
7
, at L/R ends of the Front
Panel and 1 screw
8
fixing Phone P.W.B.
Support Bracket

4
4. Main P.W.B.
1. Remove 5 screws
10
, 5 screws
11
on the Rear
Panel and detach it.
2. Remove 3 screws
12
fixing the Main P.W.B.
3. Unfasten 1 P.W.B. Holder to detach the Main
P.W.B.
4. Remove 1 screw and 2 screw fixing the
Power P.W.B.
5. Unfasten 1 P.W.B. Holder to detach the Power
P.W.B.
3. CD Mecha. Unit
1. Remove 4 screws
9
fixing the CD Mecha.
2. Unplug Connectors (b), (c) and FFC from each
socket.
3. Release the FFC from the Clamper.

5
CD TEST MODE
z Setting of the test mode
How to start the test mode: Turn on the power in the condition that CLOSE (Pin No. 3
and OPEN (Pin No. 4 of CX053 are being shorted. ( “01” is indicated on the DISPLAY
To exit from the test mode, turn off the power. (Refer to Fig. 1 “Test Point Layout”
Fig. 1 “Test Point” Layout
* Laser light of the pickup is always emitted regardless of DISC loading in the test mode.
You may lose your eyesight if you look into the laser directly.
So be careful enough when operating in the test mode.
z Used DISC: A-BEX TCD784
z Explanation of each button
* Use only the buttons described below for operations while in the test mode,
and don’t push any other buttons.
Names of buttons Operation
OPEN / CLOSE * Loads or unloads DISC
PLAY * Emits laser light
* Repeats search operation (No DISC condition: While it’s
pressed
* Actuates focus servo (In case of DISC loaded
* Actuates tracking servo
STOP * Stops operation
PAUSE * Performs auto adjustment
MANUAL SEARCH
FORWARD / REVERSE
* Moves pickup

6
z How to check the test mode
( 1 DISC discrimination, adjustment
* Insert DISC, and press the PAUSE button.
* “06 Adj” is displayed, and discrimination of DISC size 8 cm/12 cm, discrimination of
DISC reflectance (CD, CD-R/CD-RW , adjustment of focus, tracking offset,
and EF balance will be performed. (Adjusted values are not displayed: Refer to Fig. 2, 3
Fig. 2 DISC discrimination, adjustment Fig. 3
(Case of CD-RW Adjustment of EF balance
* After completing the discrimination and adjustment, it becomes stop condition.
* Once discrimination of DISC has been carried out in the “06 Adj” mode, discrimination of
size and reflectance is no longer made, and only adjustment will be performed.
( 2 Checking of servo state
* Press the PLAY button after performing above (1 “DISC discrimination, adjustment”.
* “02 L on” is displayed, and the laser will start to light. (The pickup may vibrate with a rattling
noise if DISC has been loaded, but this is not abnormal.
* Press the PLAY button again.
* “03 F on”is displayed. DISC starts turning,and focus servo will be actuated. (Refer to Fig. 4, 5
FEO
TEO
HF
DRF
TEO
TB
SLD
FEO
TEO
TEO
HF

7
¥¥¥ Fig. 4 In “03 F on”¥¥¥ ¥¥¥¥¥¥¥¥¥Fig. 5 In “03 F on”
* Press the PLAY button again.
* “04 t on” is displayed. Tracking, CLV, and slide servo will be actuated.
* Monitor HF signal using the test terminals, HF of CX053 (Pin No. 1 and
VC of CX063 (Pin No. 5 : 2.5V ref. signal . Check that the signal’s amplitude
is 1.5Vâ0.3Vp-p. (Refer to Fig. 6
¥¥¥ Fig. 6 In “04 t on”
A ( A = 1.5 ± 0.3 VP-P
HF

8
Wave-forms of each point
SPD
SPD
FEO
TEO
DRF
HF
SLD
TEO
SLD
OPEN
CLOSE
SPD
SPD
TD
TEO
HF
DRF
SLD
TEO
FD
When 12 cm DISC
start
When 8 cm DISC
start
When focus servo
on
Track search
(when forward
During PLAY
When the tray
OPEN
When 12 cm DISC
stop
When 8 cm DISC
stop
During PAUSE
Track search
(when reverse
Focus search
(no DISC
p

9
BLOCK DIAGRAM
DCD-685 only
DCD-485 only
DCD-685 only
RW SW
FOCUS
COIL Drv.
TRACKING
COIL Drv.
SLIDE
Mtr. Drv.
SPINDLE
Mtr Drv.
LOADING
Mtr. Drv.
LA6995
IC104
PICK
UP
FOCUS
COIL
TRACKIN
COIL
M
SLIDE
M
SPINDLE
M
LOADING
L.DIODE
CD MECHA
KSL-2130CCM
INMOST-SW
OPEN-SW
CLOSE-SW
ASP
LA9241M
IC101
DSP
LC78625E
IC102
H/P AMP
IC315
DAC
PCM1702
IC602/603
D.FILTER
SM5841BS
IC703
µ-COM
µPD78044F
IC201
1U-3346-1
MAIN UNIT
MUTE
MUTE
DRF
SL
SUB
CODE
CD/RW
A/D INPUT
FSEQ
KEY
MATRIX
VFD
FL601
REMOTE
SENSOR
IC702
OPT.OUT 1U-3346-4
H/P UNIT
COTROL BUS
1U-3346-3
DISPLAY
V
R
1U-3346-2
POWER
UNIT
ROTALY
ENCODER
S616
CY271
CX271
±8V
-HB
+VDD
CONTROL
XRST2
DF&DAC
PCM1735
IC105
VCO
TC9246F
IC108
XRST1
D.MUTE
MD2
LD ON
POWER CONT.
M5290P
IC501
POWER
TRANS.
PT501
AC
INLET
POWER SW
1U-3346-5
±5V
RESET
MUTE
CONTROL
PLL
BU2616F
IC107
CONTROL
DRV.MUTE

10
NOTE FOR HANDLING OF LASER PICK-UP
Description of the Components
Label
Pin Connector
year
(last figure)
day month quality control No.
Lot No.
lop No.
Oct. Nov. and Dec. are expressed by alphabetical letters
of X, Y and Z.
10 1 10-1
LD drive currentquality control
The expressed unit is by mA, with omission of the
decimal point as for example, 56.5mA will be ex-
pressed as 565, but the head of English letter means
the control in the manufacturning plant.
Pin No. Description IN/OUT
1 PD IC Vc IN
2 Vcc IN
3 E OUT
4 D OUT
5 A OUT
6 B OUT
7 C OUT
8 F OUT
KSS-213C
Lot No.
lop
Slide rack
OP Slide base
Object Lens Actuator cover
PAL-2 Flexible board
Label
Flexible flat cable connector
Z-axis
Y-axis
(Tangental direction)
X-axis
(Radial direction)
+Z-axis direction
+X-axis direction
+Y-axis direction
1 3 5 7 9 11 13 15
2 4 6 8 10 12 14 16
KSS-213C
Flexible flat cable connector
Pin No. Description IN/OUT
9 GND IN
10 LD LD IN
11 VR IN
12 PD OUT
13 FCS (+) IN
14 TRK (+) IN
15 TRK (−)IN
16 FCS (−)IN
LD
PDIC
14
13
12
11
10
987654321 16
15
TRACKING
LDPDIC
+2.5V +5V
SHORT LAND
FOCUSING
CAUTION:The soldered connecting portion must be bridged when removing CX161.