Sony HCDEH-25, HCDEH-26 Service manual

HCD-EH25/EH26

SERVICE MANUAL

Ver. 1.0 2008.05

• HCD-EH25 is the amplifi er, USB, CD player,
tape deck and tuner section in CMT-EH25.

• HCD-EH26 is the amplifi er, USB, CD player,
tape deck and tuner section in CMT-EH26.

• “WALKMAN” and “WALKMAN” logo are registered

trademarks of Sony Corporation.

• MPEG Layer-3 audio coding technology and patents

licensed from Fraunhofer IIS and omson.

Photo: HCD-EH26

CD
Section

TAPE
Section

AEP Model

HCD-EH25/EH26

UK Model

Russian Model

Korean Model

HCD-EH25

Model Name Using Similar Mechanism NEW
Base Unit Name BU-K8BD90-WOD
Optical Pick-up Name KSM-213CDP
Model Name Using Similar Mechanism HCD-EH10
Tape Transport Mechanism T ype MF-EH10

Amplifier section

European and Russian models:

DIN power output (rated):
4 + 4 watts (4 ohms at 1 kHz, DIN)
Continuous RMS power output
(reference): 5 + 5 watts (4 ohms at
1 kHz, 10% THD)
Music power output (reference):
7 + 7 watts (4 ohms at 1 kHz, 10%
THD)

Other models:

DIN power output (rated):
4 + 4 watts (4 ohms at 1 kHz, DIN)
Continuous RMS power output
(reference): 5 + 5 watts (4 ohms at
1 kHz, 10% THD)

Inputs:

AUDIO IN (stereo mini jack):
voltage 800 mV, impedance
47 kilohms

(USB) port: Type A, maximum

current 500 mA

Outputs:

PHONES (stereo mini jack): accepts
headphones of 8 ohms or more
SPEAKER: accepts impedance of
4 ohms

SPECIFICATIONS

USB section

Supported bit rate

MP3 (MPEG 1 Audio Layer-3):
32 – 320kbps, VBR

Sampling frequencies

MP3 (MPEG 1 Audio Layer-3):
32/44.1/48 kHz

CD player section

System: Compact disc and digital audio
system
Laser Diode Properties

Emission Duration: Continuous
Laser Output*: Less than 44.6µW
* is output is the value measurement

at a distance of 200mm from the
objective lens surface on the Optical
Pick-up Block with 7mm aperture.

Frequency response: 20 Hz – 20 kHz
Signal-to-noise ratio: More than 90 dB
Dynamic range: More than 90 dB

Tape deck section

Recording system: 4-track 2-channel, stereo

Tuner section

FM stereo, FM/AM superheterodyne tuner

FM tuner section:

Tuning range:

87.5 − 108.0 MHz (50 kHz step)

Antenna: FM lead antenna
Intermediate frequency: 10.7 MHz

AM tuner section:

Tuning range

Korean model:
531 − 1,602 kHz (with 9 kHz tuning
interval)
530 − 1,610 kHz (with 10 kHz tuning
interval)
Other models:

531 − 1,602 kHz (9 kHz step)
Antenna: AM loop antenna
Intermediate frequency: 450 kHz

General

Power requirements

Korean model: 220 V AC, 60 Hz

Other models: 230 V AC, 50/60 Hz
Power consumption: 27 watts
Dimensions (w/h/d) (excl. speakers):
Approx. 155 × 241 × 224.6 mm

Mass (excl. speakers): Approx. 2.2 kg

Design and specications are subject to
change without notice.

9-889-152-01

2008E05-1

2008.05

©

COMPACT DISC DECK RECEIVER

Sony Corporation

Audio Business Group
Published by Sony Techno Create Corporation

HCD-EH25/EH26

NOTES ON CHIP COMPONENT REPLACEMENT

• Never reuse a disconnected chip component.

• Notice that the minus side of a tantalum capacitor may be dam­aged by heat.

CAUTION

Use of controls or adjustments or performance of procedures
other than those specifi ed herein may result in hazardous radia-
tion exposure.

This appliance is classifi ed as
a CLASS 1 LASER product.
This marking is located on the
rear exterior.

TABLE OF CONTENTS

1. SERVICING NOTES ............................................. 3

2. GENERAL .................................................................. 4

3. DISASSEMBLY

3-1. Disassembly Flow ........................................................... 5

3-2. Rear Cabinet Block ......................................................... 5

3-3. Front Cabinet Block, Top Cabinet Block,

MAIN Board ................................................................... 6

3-4. MF-EH10 (Tape Mechanism Deck), Cassette Lid .......... 6

3-5. Base Unit Block (BU-K8BD90-WOD) .......................... 7

3-6. Optical Pick-up Block (KSM-213CDP) ......................... 7

4. TEST MODE ............................................................ 8

5. MECHANICAL ADJUSTMENTS ...................... 9

6. ELECTRICAL ADJUSTMENTS ........................ 9

7. DIAGRAMS

7-1. Block Diagram - CD SERVO Section - .......................... 12

7-2. Block Diagram - TUNER/USB Section - ....................... 13

7-3. Block Diagram - MAIN/POWER SUPPLY Section - .... 14

7-4. Printed Wiring Board - CD Board - ................................ 16

7-5. Schematic Diagram - CD Board - ................................... 17

7-6. Printed Wiring Board - USB Board - .............................. 18

7-7. Schematic Diagram - USB Board - ................................. 19

7-8. Printed Wiring Board - MAIN Board - ........................... 20

7-9. Schematic Diagram - MAIN Board (1/3) - ..................... 21

7-10. Schematic Diagram - MAIN Board (2/3) - ..................... 22

7-11. Schematic Diagram - MAIN Board (3/3) - ..................... 23

7-12. Printed Wiring Board - PANEL Board - ......................... 24

7-13. Schematic Diagram - PANEL Board - ............................ 25

7-14. Printed Wiring Board - PT-VBUS Board - ..................... 26

7-15. Schematic Diagram - PT-VBUS Board - ........................ 26

SAFETY-RELATED COMPONET WARNING!

COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE
WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.

8. EXPLODED VIEWS

8-1. Overall Section ............................................................... 27

8-2. Front Cabinet Section ..................................................... 28

8-3. Top Cabinet Section ........................................................ 29

8-4. Base Unit Section (BU-K8BD90-WOD) ........................ 30

9. ELECTRICAL PARTS LIST .............................. 43

Accessories are given in the last of the electrical parts list.

2

SECTION 1

SERVICING NOTES

HCD-EH25/EH26

NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT

The laser diode in the optical pick-up block may suffer electrostat­ic break-down because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The fl exible board is easily damaged and should be handled with
care.

NOTES ON LASER DIODE EMISSION CHECK

The laser beam on this model is concentrated so as to be focused
on the disc refl ective surface by the objective lens in the optical
pickup block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.

UNLEADED SOLDER

Boards requiring use of unleaded solder are printed with the lead­free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with

the lead free mark due to their particular size)

: LEAD FREE MARK

Unleaded solder has the following characteristics.

• Unleaded solder melts at a temperature about 40 °C higher
than ordinary solder.

Ordinary soldering irons can be used but the iron tip has to be

applied to the solder joint for a slightly longer time.

Soldering irons using a temperature regulator should be set to

about 350 °C.
Caution: The printed pattern (copper foil) may peel away if

the heated tip is applied for too long, so be careful!

• Strong viscosity

Unleaded solder is more viscous (sticky, less prone to fl ow)

than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.

• Usable with ordinary solder

It is best to use only unleaded solder but unleaded solder may

also be added to ordinary solder.

MODEL IDENTIFICATION

– Rear Cabinet –

Power Voltage
Indication

Model POWER VOLTAGE INDICATION

AEP, UK and Russian
models

Korean model AC 220 V, 60 Hz

LASER DIODE AND FOCUS SEARCH OPERATION
CHECK

During normal operation of the equipment, emission of the laser
diode is prohibited unless the upper lid is closed while turning on
the SW750. (push switch type)
The following checking method for the laser diode is operable.

• Method
Emission of the laser diode is visually checked.

1. Open the upper lid.

2. Push the SW750 as shown in Fig.1.

Note: Do not push the detection lever strongly , or it may be bent or dam-

aged.

3. Check the object lens for confi rming normal emission of the
laser diode. If not enitting, there is a trouble in the automatic
power control cirsuit or the optical pick-up.

In this operation, the object lens will move up and down 2

times along with inward motion for the focus search.

AC 230 V, 50/60 Hz

SW750

Fig.1 Method to push the SW750

3

HCD-EH25/EH26

SECTION 2

GENERAL

Guide to parts and controls

is manual mainly explains operations using the remote, but the same operations can
also be performed using the buttons on the unit having the same or similar names.

This section is extracted
from instruction manual.

Unit



Remote sensor



Playback buttons and function
buttons

Unit: USB  (play/pause)
button

Press to select the USB function.
Presstostartorpauseplaybackofan
optional USB device.

Remote: USB button

Press to select the USB function.

Unit: CD  (play/pause)
button

Press to select the CD function.
Press to start or pause playback of a disc.

Remote: CD button

Press to select the CD function.

Remote:  (play) button,
 (pause) button

Press to start or pause playback.

TUNER/BAND button

Press to select the TUNER function.
Press to select FM or AM reception
mode.

FUNCTION button

Press to select the function.



 (stop) button

Press to stop playback.



(USB) port

Connect to an optional USB device.

R

Unit: VOLUME control
Remote: VOLUME +/− button

Turn or press to adjust the volume.

RB

 (record) button,  (play)
button, / (rewind/fast
forward) button,  (stop/
eject) button,  (pause) button

Press to operate the tape functions.

RT

PHONES jack

Connect the headphones.

RE

AUDIO IN jack

Connect to an optional audio
component.

RG

STANDBY indicator

Lights up when the system is turned o.

RH

CLOCK/TIMER SELECT button
CLOCK/TIMER SET button

Press to set the clock and the Play Timer.

RI

REPEAT/FM MODE button

Press to listen to a disc or USB device
repeatedly. Or press to listen to a single
track/le or all tracks/le in a folder (for
USB devices only) repeatedly.
Press to select the FM reception mode
(monaural or stereo).

RK

ENTER button

Press to enter the settings.

RL

Battery compartment lid

RM

CLEAR button

Press to delete a pre-programmed track
le.

X

TUNER MEMORY button

Press to preset the radio station.

XB

PLAY MODE/TUNING MODE
button

Press to select the play mode of a CD or
MP3 disc.
Press to select the tuning mode.

XT

DISPLAY button

Presstochangethe informationonthe
display.

XE

SLEEP button

Press to set the Sleep Timer.

Remote

Information on the display



Timer



Text information



Play mode



DSGX



Tuner reception mode
Tuner reception



Audio format



Play/Pause



/ (power) button

Press to turn on the system.



/ (go back/go forward)
button

Press to select a track or le.

Unit: TUNING +/− (tuning)
button

Remote: +/− (tuning) button

Press to tune in the desired station.

/ (rewind/fast forward)
button

Press to nd a point in a track or le.



+/− (select folder) button

Press to select a folder.



Sound buttons
Unit: DSGX button
Remote: EQ button

Press to select the sound eect.



 PUSH OPEN/CLOSE

Press to open or close the CD
compartment.

4

DISASSEMBLY

• This set can be disassembled in the order shown below.

3-1. DISASSEMBLY FLOW

SET

3-2. REAR CABINET BLOCK
(Page 5)

3-3. FRONT CABINET BLOCK,
TOP CABINET BLOCK,
MAIN BOARD
(Page 6)

HCD-EH25/EH26

SECTION 3

3-4. MF-EH10 (TAPE MECHANISM DECK),
CASSETTE LID
(Page 6)

Note: Follow the disassembly procedure in the numerical order given.

3-2. REAR CABINET BLOCK

screw



(KTP2 3 × 8)



3-5. BASE UNIT BLOCK
(BU-K8BD90-WOD)
(Page 7)

3-6. OPTICAL PICK-UP BLOCK
(KSM-213CDP)
(Page 7)



(BVTP3 × 10)

two screws



(BVTP3 × 10)

screw



(KTP2 3 × 8)

two screws

connector



(CN002)

connector



(CN103)

two screws



(BVTP3 × 10)

rear cabinet block



5

HCD-EH25/EH26

3-3. FRONT CABINET BLOCK, TOP CABINET BLOCK, MAIN BOARD

top cabinet block

R

two screws





(Russian, Korean models),
flexible flat cable (7 core) (FFC001)
(AEP, UK models)
(CN106)

two connectors



(CNP501, CNP502)

flexible flat cable (17 core)



(FFC002) (CN105)

flexible flat cable (5 core) (FFC001)

MAIN board

RB

claw



(BVTP2.6)

claw



claw

connector



(SW750)

claw



front cabinet block



claw



REC lever

Note: Adjust so that the space of slide switch (REC/PB) (SW501)

3-4. MF-EH10 (TAPE MECHANISM DECK), CASSETTE LID

screw



(BVTP2.6)

flexible flat cable (FFC003)



(CN201)

slide switch (REC/PB) (SW501)

2.3 ± 0.4 mm

REC lever becames 2.3 ± 0.4 mm

screw

lever (REC)





.

two screws



(BVTP2.6)

PWB holder



cassette lid

RE

Note: When removing cassette lid,
it's possible to remove cassette
lid by the order of   RT RE.

two claws

RT

Open the button cover (C).



6

Push the eject button.





two screws



cable holder

R

two screws



(BVTP2.6)

MF-EH10

RB

(tape mechanism deck)

3-5. BASE UNIT BLOCK (BU-K8BD90-WOD)

Note: This illustration sees the top cabinet block back side from back.

HCD-EH25/EH26

four screws



(PWH B2.6)

base unit block



(BU-K8BD90-WOD)

two vibration proof rubbers



(green)





CD cover





(red)

four claws

top cabinet block

– Bottom view –

two vibration proof rubbers

3-6. OPTICAL PICK-UP BLOCK (KSM-213CDP)

Remove the four solders.



optical pick-up block



(KSM-213CDP)

wire (flat type) (16 core)



(optical pick-up, CD board: CN301)

CD board



7

HCD-EH25/EH26

SECTION 4

TEST MODE

COLD RESET

The cold reset clears all data including preset data stored in the
memory to initial conditions. Execute this mode when returning
the set to the customer.

Procedure:

1. Press three buttons of [x], [l

. –

TUNING] and [

?/1

simultaneously.

2. When “RESET” appears, the set enters standby status.

PANEL TEST MODE
Procedure:

1. Press the [

2. Press three buttons of [FUNCTION], [USB], and [

] button to turn the power on.

?/1

?/1

] simul-

taneously.

3. When the panel test is activated, [STANDBY] LED and seg­ments on the liquid crystal display are all turned on.

4. Press the [CD

u] button, date and version are displayed. For

example, “0403V101”.

5. Press the [TUNER/BAND] button, model name and destina­tion are displayed. For example, “EH25CE2”.

6. To release from this mode, press three buttons of [FUNC
TION], [USB], and [

] simultaneously.

?/1

TUNER STEP CHANGE
(EH25: Korean)

The AM tuning interval can be changed over 9 kHz or 10 kHz.

Procedure:

1. Press the [

] button to turn the power on.

?/1

2. Press the [TUNER/BAND] button to select TUNER (AM)
function.

3. Press the [

] button again to turn the power off (standby).

?/1

4. After pressing the [DISPLAY] button on the remote command­er, while pressing the [TUNING + M L] button, press the
[

] button.

?/1

5. It turns power on and display “9K STEP” or “10K STEP”, and
thus the tuning interval is changed over.

CD SERVICE MODE

This mode can move the SLED of the optical pick-up, and also can
turn the optical pick-up laser power on and off.

Procedure:

1. Press the [

] button to turn the power on.

?/1

2. Press the [FUNCTION] button to select CD function.

3. Press three buttons of [l m – TUNING], [FUNCTION],
and [

] simultaneously.

?/1

4. It enters the CD service mode and displays “SERVICE”.

5. To release from this mode, press three buttons of [l m
– TUNING], [FUNCTION] and [

] simultaneously.

?/1

Key Operation:

[TUNING + M L], [l m – TUNING]:

Use these keys to move the SLED. When [TUNING + M

L] is pressed in this mode, the SLED moves to outer cir-

cumference and the message “SLED OUT” is displayed.

When [

l m – TUNING] is pressed in this mode, the

SLED moves to inner circumference and the message
“SLED IN” is displayed.

CD ERROR CODE

The past errors of the optical pick-up system (= optical unit + CD
board) are displayed as the BD Errors as shown below.

Procedure:

1. Press the [

]

2. Press the [FUNCTION] button to select CD function.

] button to turn the power on.

?/1

3. Press three buttons of [l m – TUNING], [DSGX] and
[

] simultaneously.

?/1

4. Then, the BD error code is displayed as “D0xxxxxx” (x means
hexadecimal number) on the liquid crystal display as shown
below.

5. Every pressing of the [TUNING +

M L] button in this

mode increments the number after “D” starting from “D0” up
to “D4”, and then returns to “D0”. Every pressing of the [

m – TUNING] button in this mode decrements the number

after “D”. The smaller the error code number is, the newer the
error content is.

6. To release from this mode, press the [

] button to turn the

?/1

power off.

Contents of “BD Errors”

Error display example

D 0 01 06 01

1 2 3 4

1 It indicates the error history number

0 to 4: The error code number 0 indicates the newest error.

2 It indicates the error content
01: The focus servo cannot lock-in.
02: GFS is no good (NG).
03: The startup time exceeds the specifi ed period of time

(time over)

04: The focus servo is unlocked continuously.
05: Q code cannot be obtained within the specifi ed period of

time.

06: The tracking servo cannot lock-in.
07: Blank disc

3 It indicates the on-going processing of optical pick-up system

(= optical unit + CD board) when the trouble has occurred.

01: The CD SHIP mode processing is in progress.
02: The POWER OFF processing is in progress.
03: The POWER ON processing is in progress.
04: The INITIALIZE processing is in progress.
05: The optical pick-up system (= optical unit + CD board)

is in the stop state.

06: The STOP operation is in progress.
07: The startup processing is in progress.
08: The TOC read-in processing is in progress.
09: The SEARCH operation is in progress.
0A: The PLAY operation is in progress.
0B: The PAUSE operation is in progress.
0C: The PLAY – MANUAL SEARCH operation is in prog-

ress.

0D: The PAUSE – MANUAL SEARCH operation is in prog-

ress.

l

[FUNCTION]:

Use this key to turn the optical pick-up laser power on and

off. When the laser power is turned on, the message “LD
ON” is displayed. When the laser power is turned off, the
message “LD OFF” is displayed.

8

4 It indicates the operation that is being processed when the trou-

ble has occurred.

It indicates the step number of each processing specifi ed by 3.

Because the numbers of steps are different in each processing,
this number is different in each processing.

SECTION 5

MECHANICAL ADJUSTMENTS

HCD-EH25/EH26

SECTION 6

ELECTRICAL ADJUSTMENTS

Precaution

1. Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback head pinch roller
erase head rubber belts
capstan idlers

2. Demagnetize the record/playback head with a head demag­netizer. (Do not bring the head magnetizer close to the erase
head.)

3. Do not use a magnetized screwdriver for the adjustments.

4. After the adjustments, appiy suitable locking compound to the
parts adjusted.

5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.

Torque Measurement

Mode Torque meter Meter reading

FWD CQ-102AS

FWD
Back Tension

FF CQ-201AS

REW CQ-201B

CQ-102C

2.0 – 8.0 mN • m
(20 – 80 g • cm)

(0.28 – 1.12 oz • inch)

0.15 – 0.6 mN • m
(1.5 – 6.0 g • cm)

(0.021 – 0.083 oz • inch)

5.0 – 17.7 mN • m
(50 – 177 g • cm)

(0.7 – 2.48 oz • inch)

5.0 – 17.7 mN • m
(50 – 177 g • cm)

(0.7 – 2.48 oz • inch)

Tape Tension Measurement

Mode Torque meter Meter reading

FWD CQ-403A

more than 80 g

(more than 2.82 oz)

DECK SECTION 0 dB = 0.775

1. Demagnetize the record/playback head with a head
demagnetizer.

2. Do not use a magnetized screwdriver for the adjustments.

TEST TAPE

Tape Signal Used for

P-4-A063 6.3 kHz, –10 dB Azimuth Adjustment

RECORD/PLAYBACK HEAD AZIMUTH ADJUSTMENT
Procedure:

1. Mode: Playback

test tape
P-4-A063
(6.3 kHz, –10 dB)

2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.

L-CH
peak

Output
level

R-CH

Screw
position

peak

set

within
1 dB

L-CH
peak

MAIN board
PHONES jack
(J102)

R-CH
peak

level meter

+
–

within
1 dB

Screw
position

3. Mode: Playback

test tape
P-4-A063
(6.3 kHz, –10 dB)

in phase 45° 90° 135° 180°

MAIN board
PHONES jack
(J102)

set

waveform of oscilloscope

good

oscilloscope

V

wrong

H

4. Confi rm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.

9

HCD-EH25/EH26

Adjustment Location: Record/Playback/Erase Head

Note: Remove the cassette lid before this adjustment.

Refer to “DISASSEMBLY” (page 5)

TUNER SECTION

0 dB = 1 μV

[AM]
Setting:

Function: TUNER
Band: AM

60 cm

loop antenna A

AM RF signal
generator

30% amplitude
modulation by
400 Hz signal

loop antenna B

set

[FM]
Setting:

Function: TUNER
Band: FM

MAIN board
JW403

FM RF signal

generator

MAIN board
CNP802 pin 

(TUNER OUT L-ch)

level meter

• Repeat the procedures in each adjustment several times, and
the tracking adjustments should be fi nally done by the trimmer
capacitors.

• Remove FM antenna in FM adjustment.

( ): AEP, Russian and UK models

AM VT VOLTAGE ADJUSTMENT

Adjustment Part Frequency Display Reading on Digital Voltmeter

L852 530 (531) kHz 1.5 ± 0.1 V

Confi rmation 1710 (1602) kHz 8.0 (7.2) ± 0.5 V

( ): AEP, Russian and UK models

AM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter

L851 530 (531) kHz

FM VT VOLTAGE ADJUSTMENT

Adjustment Part Frequency Display Reading on Digital Voltmeter

L805 87.5 MHz 1.75 ± 0.1 V

Confi rmation 108 MHz 6.2 ± 0.5 V

FM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter

L804 98 MHz

FM DETECTOR ADJUSTMENT
Setting:

Function: TUNER
BAND button: FM

FM RF Signal
generator

Carrier frequency : 98 MHz
Modulation : deviation by

FM 75 kHZ

Output level : 60 dB

MAIN board
JW403
(TUNER OUT L-ch)

set

MAIN board
JW148 (GND)

1. Tune the set to 98 MHz.

2. Adjust L806 so that modulation distortion may become the
best in the vicinity of the maximum value where the tuner out
level becomes -156Bs or more.

1 kHz frequency
deviation by FM 75 kHz
signal
Output level:
as low as possible

JW821 (VT)

JW805 (GND)

10

MAIN board
CNP802 pin 

MAIN board

set

digital voltmeter

10 kΩ

+
–

MAIN board
JW148
(GND)

HCD-EH25/EH26

V

Adjustment Location:

– MAIN Board (Component Side) –

L805

FM VT

Voltage

Adjustment

L806

FM Detector

Adjustment

L804

FM Tracking

Adjustment

– MAIN Board (Conductor Side) –

CNP802

JW805

(GND)

1
3

L852

AM VT

Voltage

Adjustment

L851

AM Tracking

Adjustment

JW403

(TUNER OUT L-ch)

CD SECTION

Note:

1. CD Block is basically constructed to operate without adjustment.

2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.

3. Use an oscilloscope with more than 10 MΩ impedance.

4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specifi ed value with the following checks.

5. Check the focus bias check when optical pick-up block is replaced.

FOCUS BIAS CHECK

oscilloscope

(DC range)

CD board

TP122 (RFEQO)
TP124 (VC)

Procedure:

1. Connect oscilloscope to TP122 (RFEQO) and TP124 (VC) on
the CD board.

2. Press the [

] button to turn the power on.

?/1

3. Set the disc (YEDS-18) and press the [CD u] button to play­back.

4. Confi rm that oscilloscope waveform is as shown in the fi gure
below. (eye pattern)

A good eye pattern means that the diamond shape (◊) in the

center of the waveform can be clearly distinguished.

+
–

VOLT/DIV: 200 m
TIME/DIV: 500 ns

JW821

(VT)

JW148

(GND)

JW402

(TUNER OUT R-ch)

FM TUNE LEVEL CHECK

signal

generator

set

Procedure:

1. Turn on the set.

2. Input the following signal from signal generator to FM antenna
input directly.

Carrier frequency : A = 87.5 MHz, B = 98 MHz, C = 108 MHz
Deviation : 75 kHz
Modulation : 1 kHz
ANT input : 35 dBu (EMF)

Note: Use 75 ohm coaxial cable to connect signal generator and the set.

You cannot use video cable for checking.

Use signal generator whose output impedance is 75 ohm.

Checking Location:

– CD Board (Conductor Side) –

TP124

(VC)

TP122

(RFEQO)

level:

1.2 ± 0.3 Vp-p

IC101

3. Set to FM tuner function and tune A, B and C signals.

4. Confi rm “TUNED” is lit on the display for A, B and C sig-
nals.

When the selected station signal is received in good condition,
“TUNED” is displayed.

11

HCD-EH25/EH26

SECTION 7

DIAGRAMS

7-1. BLOCK DIAGRAM - CD SERVO Section -

AVDD

DETECTOR

A

B

C

D

E

F

LASER DIODE

PD

LD

I-V AMP

VCC

+3.3V

A

B

C

D

E

F

AUTOMATIC

LD

PD

POWER

CONTROL

Q301

FNi1 (A)

95

97 FPi1 (B)

94 FNi2 (C)

96 FPi2 (D)

100 TNi (E)

98 TPi (F)

91 LDo 92MDi

RFo

89

3RFRP RFZI

88

2

76TEi TEZi

AGCi

83RFEQo 81 RFi

82 RFRPi

30LO

27RO

R-CH

CD-L

(Page 14)

A

OPTICAL PICK-UP

BLOCK

(KSM-213DCP)

M401

(SPINDLE)

M402

(SLED)

2-AXIS

DEVICE

(TRACKING)(FOCUS)

VC

SP+

M

SP–

SL+

M

SL–

T+

T–

F+

F–

R-ch is omitted due to same as L-ch.

SIGNAL PATH

: CD PLAY

FOCUS/TRACKING COIL DRIVE,

SLED/SPINDLE MOTOR DRIVE

IC401

BIAS 23

2VO1+

3

IN1

1VO1–

12 VO2–

IN2’ 9

11 VO2+

18 VO3+

17 VO3–

26 VO4+

27

VO4–

MUTE

7

IN3’

IN4’

DVDD

+3.3V

20

24

S201

(LIMIT)

84 VRo

13 DMo

12 FMo

10 TRO

9FMO

20 IO0 (/HSO)

CD-MP3 PROCESSOR

IC101

SYSTEM CONTROLLER

IC701 (1/3)

38BUS0

39BUS1 6BUS1

40BUS2 (SO) 7BUS2

41BUS3 (SI) 8BUS3

42BUCK (CLK)

43XCCE

48PIO0

5BUS0

10 BUCK

11 XCCEN

3REQ

12

XI
23

X102

16.9344MHz

54SBSY
37XRST

XO

24

43 SBSY
12 XRST

4 MMUT

HCD-EH25/EH26

HCD-EH25/EH26

1313

7-2. BLOCK DIAGRAM - TUNER/USB Section -

FM MIX

AMP

Q803

FM/AM TUNER,

FM/AM PLL

IC801

RDS DECODER

IC861

36

FMRF-IN

8

FMIF-IN

22

MPX-IN

1

AMRF-IN

31

AM-OSC

25

TU_DO

56

TU_CLK

55

TU_CE

57

TU_DI

39

TU_ASD

SYSTEM CONTROLLER

IC701 (2/3)

+4V

REGULATOR

Q862

VM +9V RDS +4V

X801

75kHz

2019

XIN

XOUT

16DI17CL15

CE

18

DO25AGC

1

CNP802

ANTENNA

FM/AM

3

BAND-PASS

FILTER
BPF801

AM

TRACKING

L851

AM-RF

AM VT

VOLTAGE

L852

AM-OSC

D851

CF801

7

AMIF-IN

L803

AM-IFT

34

FMRF-OUT

FM

TRACKING

L804

FM-RF

32

FM-OSC

FM VT

VOLTAGE

L805

FM-OSC

VM +9V

11

FM-DET

FM

DETECTOR

L806

FM-DET

3

FM-MIX

30BO2

23

FMDET-OUT

12

L-OUT

13

R-OUT R-CH

TUNER-L

5

AM-MIX

24

AMDET-OUT

CF802

CF803

4

FIN

DET AMP

Q861

26

RDS_DATA

2

D0

45

RDS_CLK

16

CL

X861

4.332MHz

1413

XIN

XOUT

B

• SIGNAL PATH

: AM

• R-ch is omitted due to same as L-ch.

: FM

(EH25: AEP, UK/EH26)

3

CN104

(USB)

D+

D–

2

USB CONTROLLER

IC101

D/A CONVERTER

IC105

USB_DP34

USB_DM

33

DATA

55

LRCK

53

BCK

54

DIN1
LRCI

3

MCLK

2

VOUTL 8

VOUTR

5

XOUT_PLL

XIN_PLL

40 41

X101

16.9344MHz

CLOCK SHIFT

IC104

MCLK

4

RESETX

1

SDA

13

SCL

12

BUSY

11

MCHNG

10

USB_SDA

49

USB_SCL

50

USB_BUSY

19

MCHING

18

USB_RESET

17

: USB

R-CH

C

USB-L

(Page 14)

(Page 14)

HCD-EH25/EH26

HCD-EH25/EH26

1414

7-3. BLOCK DIAGRAM - MAIN/POWER SUPPLY Section -

R-CH

INPUT SELECTOR,

ELECTRICAL VOLUME

IC401

28

REC1O

18

OUT1

13

SD

23

C1

21

B1

2

PB1P

19

A1

R-CH

CD-L

A

TUNER-L

• SIGNAL PATH

: CD PLAY

: TAPE PLAY
: REC

• R-ch is omitted due to same as L-ch.

J105

AUDIO IN

J102

PHONES

SPEAKER

+
–

–

+

R

L

J101

BIAS OSC

L501

OSC

Q507

TPR501

(REC/PB)

TAPE

MECHANISM

DECK

L-CH

SW501-1

SW501

(REC/PB)

PB

S

REC

R-CH

R-CH

POWER

AMP

IC301

33

FUNC_SDA

RMC

9

SYSTEM CONTROLLER

IC701 (3/3)

+

(AC IN)

F001

POWER

TRANSFORMER

PT005

SYS +3.3V

D702

D116 – 118

D372

AMP B+

RECT

D107 – 110

B+ SWITCH

Q351, 352

AC DETECT

Q371, 372

AC DETECT

Q121, 122

VOLTAGE

DETECT

Q705, 706

RECT

D111, 113

VSTBY

+9V

REGULATOR

Q101 – 103

VM +9V

USB

DVDD +3.3V

VM +7V

TUNER +5V

TUNER +3V

46POWER_ON

42HOLD

36P_MONI

54REST

REMOTE CONTROL

RECEIVER

IC703

LED DRIVE

Q707

LED701

(LCD BACK LIGHT)

LED_STBY

22

LED

1

LED702

X701

32768Hz

14 13

X3

X2

92 93

X702

5.53MHz

X1

X0

LCD702

LIQUID

CRYSTAL

DISPLAY

48 RE_VOL

2 CD OPEN/CLOSE

ROTARY

ENCODER

SW700

VOLUME

STANDBY

SW701 – 711

(FRONT PANEL KEYS)

SW750

(CD LID OPEN/CLOSE DETECT)

KEY1 – KEY3

37, 38, 41

COM0 – COM3

59 – 62

SEG0 – SEG31

63, 64, 67 – 89, 94 – 100

RESET

SWITCH

Q704

B

SW501-2

40

TP_STATE

DC

DETECT

Q123

LED DRIVE

Q711, 712

LINE FILTER

LF901

REGULATOR

Q701 – 703

REGULATOR

Q802

REGULATOR

Q801

+3.3V

REGULATOR

IC707

+3.5V

REGULATOR

IC706

D703

+1.5V

REGULATOR

IC201

+1.5V

REGULATOR

IC102

VOLTAGE

DETECTOR

IC709

Q710

D704, 705

B+ SWITCH

Q713, 714

USB AVDD +3.3V

USB +1.5V

AVDD +3.3V

DVDD +3.3V

VDD +1.5V

24USB_REG_ON

23CD_ON

RECT

D901, 902

+5V

REGULATOR

IC901

VBUS POWER

ON/OFF SWITCH

IC103

VBUS B+

AUDIO SELECT

SWITCH

IC451

USB-L

C

: USB

: AUDIO IN

: FM

30

AUDIO_SW

34

AMP_ON

21

USB_EN

20

USB_FLG

+

+3.3V

REGULATOR

Q708

+3.3V

REGULATOR

Q709

(Page 12)

(Page 13)

(Page 13)

HCD-EH25/EH26

HCD-EH25/EH26

1515

For Schematic Diagrams.

Note:

• All capacitors are in μF unless otherwise noted. (p: pF) 50
WV or less are not indicated except for electrolytics and
tantalums.

• All resistors are in Ω and 1/4 W or less unless otherwise
specifi ed.

• f : internal component.

• C : panel designation.

THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)

• A : B+ Line.

• H : adjustment for repair.

• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.

– CD board –

no mark : CD PLAY

– USB board –

no mark : USB

– Other board –

no mark : FM

[ ] : AM
( ) : CD PLAY
‹‹ ›› : USB
< > : TAPE PLAY
{ } : REC
* : Impossible to measure

• Voltages are taken with VOM (Input impedance 10 MΩ).

Voltage variations may be noted due to normal production

tolerances.

• Waveforms are taken with a oscilloscope.

Voltage variations may be noted due to normal production

tolerances.

• Circled numbers refer to waveforms.

• Signal path.

F : FM
f : AM
J : CD PLAY
N : USB
E : TAPE PLAY
j : REC
h : AUDIO IN

• Abbreviation

KR : Korean model
RU : Russian

model

For Printed Wiring Boards.

Note:

• X : Parts extracted from the component side.

• Y : parts extracted from the conductor side.

• W : indicates side identifi ed with part number.

• f : internal component.

• : Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)

• Indication of transistor.

Note: The components identifi ed by mark 0 or dotted

line with mark 0 are critical for safety.

Replace only with part number specifi ed.

Caution:

Pattern face side:
(Conductor Side)
Parts face side:
(Component Side)

Parts on the pattern face side seen from
the pattern face are indicated.
Parts on the parts face side seen from
the parts face are indicated.

• Circuit Boards Location

C
Q

B

E

These are omitted.

MAIN board

PANEL board

CD board

PT-VBUS board

USB board

HCD-EH25/EH26

HCD-EH25/EH26

1616

• : Uses unleaded solder.

• See page 15 for Circuit Boards Location.

7-4. PRINTED WIRING BOARD - CD Board -

R150

R149

R148

R108

R154

R153

C148

C110

C109

C301

C303

C302

C104

R110

C116

C404

R203

R204

R205

R206

R207

R208

R209

R210

R219

R223

R222

R147

R221

R218

R146

R145

C150

R113

C403

R202

C151

C108

C105

C147

C146

C145

C152

C118

C117

C144

C101

C125

CN201

C143

C120

R144

R157

C142

C141

C140

C100

C107

R408

R156

C124

C127

C126

CN301

R101

C119

C102

R415

R414

C103

R405

C113

R102

R402

R105

R106

C132

C138

C137

R135

R134

R136

R130

R128

R129

R143

R139

C136

R120

R114

C153

C112

R125

R126

C149

C139

R127

R118

R140

R151

C122

C123

R220

R104

S201

R155

C128

C106

C201

R304

R302

C309

C205

C207

C307

R303

C133

R111

R112

C115

R211

Q301

R301

C204

C202

C206

C306

R212

C401

C130

C405

IC201

IC401

IC101

R201

R142

CD BOARD (COMPONENT SIDE)

CD BOARD (CONDUCTOR SIDE)

314

5

17 814

28 22 21 15

TP124

(VC)

TP122

(RFEQO)

1

25

26

50

5175

76

100

1

21

A

PANEL
BOARD
CNP701

161

1-872-135-

11

(11)

1-872-135-

11

(11)

OPTICAL PICK-UP BLOCK

(KSM-213CDP)

A

B

C

D

E

F

123456789

E

(LIMIT)

M401

(SPINDLE)

M402

(SLED)

M

M

X102

(Page 24)

HCD-EH25/EH26

HCD-EH25/EH26

1717

• See page 23 for Waveforms. • See page 27 for IC Block Diagrams. • See page 33 for IC Pin Function Description.

7-5. SCHEMATIC DIAGRAM - CD Board -

R108

R154

R153

C201

R304

R201

R110

R303

R203

R204

R205

R206

R207

R208

R209

R210

R219

R223

R222

R221

R218

R112

R202

R211

Q301

R301

C202

R157

TP122 (RFEQO)

TP124 (VC)

R156

CN301

R101

C401

R415

R102

R128

R129

R143

R142 R139

R114

R140

R151

R220

R150

R212

IC101

R105

R106

R125

R126

R127

IC201

X102

C301

C307

C309

C100

C138

C153

C151

C204

C130

C128

C113

C127

C126

C103

C102

C120

C118

C117

C101

C124

C125

R145
R146
R147
R148
R149

C149

C105

C143

C146
C145

C148

C104

C405

C404

C403

C205

C116

C133

CN201

C110

R113

R111

C115

R155

C109

C132

R104

C123

C122

C139

C150

R136 R135

R134

C112 C108

R120

R118

C136

C107

R130

R144

C144

C147

C140

C137

C141
C142

C106

R302

C306

C303C302

R405

R402

R408

R414

C207

C152

C206

IC401

0

1M

1M

100
10V

2.2

0

10k

2.2

100

100

100

100

100

100

100

100

100k

100k

100k

100k

100k

100

0

100

2SA2119K

100k

100
10V

100
100

16P

220

220
10V

47k

10k

470k

1k

47k

22k 47k

10k

0

0

100k

0

TK63115SCL-G@GT

0.1

1

0.001

0.1

470p

0.1

470p

0.1

0.1

0.0022

0.1

0.1

0.1

0.01

0.01

0.022
C119

0.022

0.1

0.0047

0.0047

0
0
0
0
0

22p

0.1

0.01

470p

0.01

47p

0.1

0.1

0.1

0.1

0.1

0.1

0.1

0.1

10k

100

22

6.3V

47

0.1

0.1

0

470p

470p

0.01

0.001

22k 470k

1M

0.1 0.1

47p

0.1

4.7k

22k

0.1

0.1

0.01

0.01

0.0022

0.1

100
10V

0

100
10V

1010

10k

2.2k

2.2k

4.7k

1

470p

1

BA5826SFP-E2

SP-

SP+

SL+

SL-

100

1M

1k

0

0

0

16.9344MHz

TC94A70FG-006

5p

5p

21P

0

100k

IC101

CD-MP3 PROCESSOR

IC401

FOCUS/TRACKING COIL DRIVE,

SLED/SPINDLE MOTOR DRIVE

IC201

+1.5V REGULATOR

SP­SP+

SL+

SL-

M401

(SPINDLE)

M402

(SLED)

AUTOMATIC POWER

CONTROL

S201

(LIMIT)

IC B/D

A

PANEL
BOARD
CNP701

2

1

IC B/D

OPTICAL
PICK-UP

BLOCK

(KSM-213CDP)

M

M

(Page 25)