SHARP CD-DH790N Diagram

CD-DH790N

SERVICE MANUAL

No. S8938CDDH790N

MINI COMPONENT SYSTEM

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IN

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CD

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IN

DIO

AU

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PHO

FUNCTIO

VOL

H

PUS

N
E

OP

MODEL

CD-DH790N

CD-DH790N Mini Component System consisting of
CD-DH790N (main unit) and CP-DH790N (speaker system).

• In the interests of user-safety the set shoul d be restored
to its original condition and only parts identical to those
specified be used.

iPod is a trademark of Apple Inc.,
registered in the U.S. and other countries.

“Made for iPod” means that an electronic accessory has
been designed to connect specifically to iPod and has been
certified by the developer to meet Apple performance
standards.

CONTENTS

PRECAUTIONS FOR USING LEAD-FREE SOLDER
CHAPTER 1. GENERAL DESCRIPTION

[1] Important Service Safety Precaution.............. 1-1

[2] Important Service Notes (for U.S.A only).......1-1

[3] Specifications................................................. 1-2

[4] Name Of Parts ............................................... 1-3

CHAPTER 2. ADJUSTMENTS

[1] Mechanism Section........................................ 2-1

CHAPTER 3. MECHANISM BLOCKS

[1] Caution On Disassembly................................ 3-1

CHAPTER 4. DIAGRAMS

[1] Main Block Diagram....................................... 4-1

[2] Servo Block Diagram ....................................4-3

Apple is not responsible for the operation of thi

s device or its

compliance with safety and regulatory standards.

CHAPTER 5. CIRCUIT DESCRIPTION

[1] Waveforms Of CD Circuit ..............................5-1

[2] Voltage...........................................................5-2

CHAPTER 6. CIRCUIT SCHEMATICS AND PARTS
LAYOUT

[1] Notes On Schematic Diagram.......................6-1

[2] Types Of Transistor And LED........................6-1

[3] Schematic Diagram.......................................6-2

[4] Charts Of Connecting Wires .......................6-22

[5] Wiring Side Of PWB....................................6-24

CHAPTER 7. FLOWCHART

[1] Troubleshooting.............................................7-1

CHAPTER 8. OTHERS

[1] Function Table Of IC......................................8-1

[2] FL Display............................. ... ...... .... ... ... ... ...8-9

PARTS GUIDE

Parts marked with " " are important for maintaining the safety of the set. Be sure to replace these parts with

!

specified ones for maintaining the safety and performance of the set.

This document has been published to be used

SHARP CORPORATION

for after sales service only.
The contents are subject to change without notice.

CD-DH790N

PRECAUTIONS FOR USING LEAD-FREE SOLDER

1.Employing lead-free solder

"MAIN, POWER, DISPLAY, SPACER, REGULATOR, TAPE, SERVO, iPod PWB" of this model employs lead-free
solder. The LF symbol indicates lead-free solder, and is attached on the PWB and service manuals. The
alphabetical character following LF shows the type of lead-free solder.

Examples:

Indicates lead-free solder of tin, silver and copper.

2.

Using lead-free wire solder

When fixing the PWB soldered with the lead-free solder, apply lead-free wire solder. Repairing with conventional
lead wire solder may cause damage or accident due to cracks.
As the melting point of lead-free solder (Sn-Ag-Cu) is higher than the lead wire solder by 40°C, we recommend
you to use a dedicated soldering bit, if you are not familiar with how to obtain lead-free wire solder or soldering
bit, contact our service station or service branch in your area.

3.

Soldering

As the melting point of lead-free solder (Sn-Ag-Cu) is about 220°C which is higher than the conventional lead
solder by 40°C,and as it has poor solder wettability, you may be apt to keep the soldering bit in contact with the
PWB for extended period of time. However, since the land may be peeled of for the maximum heat-resistance
temperature of parts may be exceeded, remove the bit from the PWB as soon as you confirm the steady
soldering condition.
Lead-free solder contains more tin, and the end of the soldering bit may be easily corrected. Make sure to turn
on and off the power of the bit as required.
If a different type of solder stays on the tip of the soldering bit, it is alloyed with lead-free solder. Clean the bit
after every use of it.
When the tip of the soldering bit is blackened during use, file it with steel wool or fine sandpaper.
Be careful when replacing parts with polarity indication on the PWB silk.

Lead-free wire solder for servicing

Ref No.

PWB-A 92LPWB7773MANS MAIN (A1), POWER (A2), DISPLAY (A3), SPACER (A4), REGULATOR (A5), TAPE (A6)
PWB-B RUITKA036AWZZ SERVO
PWB-C 92LPWB7119PODS iPod

Parts No.

Description

– i –

CD-DH790N

CHAPTER 1. GENERAL DESCRIPTION

[1] Important Service Safety Precaution

CAUTION : “These servicing instructions are for use by qualified service personnel only. To reduce
the risk of electric shock do not perform any servicing other than that contained in the operating
instructions unless you are qualified to do so”.

WARNING

1. For continued safety, no modification of any circuit should be attempted.

2. Disconnect AC power before servicing.

CAUTION: FOR CONTINUED
PROTECTION AGAINST FIRE
HAZARD, REPLACE ONLY WITH
SAME TYPE F801, F802, F805 5A, 125V/
F80, F804 2.5A, 125V/
F808 1.6A, 125V FUSES.

ATTENTION: POUR ASSURER
UNE LONGUE PROTECTION CONTRE
UN INCENDIE, REMPLACER SEULEMENT
PAR UN FUSIBLE DE
TYPE F801, F802, F805 5A, 125V/
F803, F804 2.5A, 125V/
F808 1.6A, 125V FUSES.

[2] Important Service Notes (for U.S.A only)

BEFORE RETURNING THE AUDIO PRODUCT

(Fire & Shock Hazard)
Before returning the audio product to the user,

perform the following safety checks.

1. Inspect all lead dress to make certain that leads
are not pinched or that hardware is not lodged
between

the chassis and other metal parts in the

audio product.

2. Inspect all protective devices such as insulating
materials, cabinet, terminal board, adjustment and
compartment covers or shields, mechanical
insulators etc.

3. To be sure that no shock hazard exists, check for
leakage current in the following manner.

Plug the AC line cord directly into a 120 volt AC

*
outlet.

Using two clip leads, connect a 1.5k ohm, 10

*
watt resistor paralleled by a 0.15µF capacitor in

series with all exposed metal cabinet parts and
a known earth ground, such as conduit or
electrical ground connected to earth ground.

Use a VTVM or VOM with 1000 ohm per volt, or

*
higher, sensitivity to measure the AC voltage drop

across the resistor (See diagram).

Connect the resistor connection to all exposed

*
metal parts having a return path to the chassis

(antenna, metal cabinet, screw heads, knobs and
control shafts, escutcheon, etc.) and measure the
AC voltage drop across the resistor.

VTVM

AC SCALE

1.5k ohms
10W

0.15 µ F

TEST PROBE

TO EXPOSED
METAL PARTS

CONNECT TO
KNOWN EARTH
GROUND

All check must be repeated with the AC line cord plug
connection reversed.

Any reading of 0.3 volt RMS (this corresponds to 0.2
milliamp. AC.) Or more is excessive and indicates a
potential shock hazard which must be corrected before
returning the audio product to the owner.

1 – 1

–2

CD-DH790N

[3] Specifications

General

Power source AC 120 V ~ 60 Hz
Power

consumption
Dimensions Width: 9 - 7/16" (240 mm)

Weight 8.8 lbs. (5.4 kg)

55 W

Height: 12 - 7/16" (315.5 mm)
Depth: 11 - 5/32" (283.2 mm)

Amplifier

Output power PMPO: 2800 watts

Output terminals Speakers: 4 ohms

Input terminals Audio In (audio signal):

RMS: Total 200 watts
(100 watts per channel into 4
ohms at 1 kHz, 10% total
harmonic distortion)
FTC: 75 watts minimum RMS per
channel into 4 ohms from 100
Hz to 20 kHz, 10% total
harmonic distortion.

Headphones: 16 - 50 ohms
(recommended: 32 ohms)

250 mV/47 k ohms

CD player

Type Single disc multi-play compact disc

Signal readout Non-contact, 3-beam

D/A converter Multi bit D/A converter
Frequency

response
Dynamic range 90 dB (1 kHz)

player

semiconductor laser pickup

20 - 20,000 Hz

Cassette deck

Frequency
response

Signal/noise
ratio

Wow and flutter 0.35% (WRMS)

50 - 14,000 Hz (normal tape)

50 dB (playback)

USB

USB host interface Complies with USB 1.1 (Full

Support file MPEG 1 Layer 3

Bitrate support MP3 (32 ~ 320 kbps)

Other Maximum total number of

File system
support

Speed)/ 2.0 Mass Storage
Class.

Support Bulk only and CBI
protocol.

WMA (Non DRM)

WMA (64 ~ 160 kbps)

MP3/WMA files is 1024.
Maximum total number of

folders is 255 INCLUSIVE of
root directory.

The ID3TAG information
supported are TITLE, ARTIST
and ALBUM only.

Supports ID3TAG version 1
and version 2.

Support USB devices with
Microsoft Windows/DOS/FAT
12/ FAT 16/ FAT 32.

2 kbyte block length for sector.

Tuner

Frequency range FM: 87.5 - 108 MHz

AM: 530 - 1,720 kHz

Speaker

Type 2-way type speaker system

Maximum input
power
Rated input power 100 W
Impedance 4 ohms
Dimensions Width: 7-1/16" (180 mm)

Weight 6.0 lbs. (2.7 kg)/each

2" (5 cm) tweeter
5-1/8" (13 cm) woofer

200 W

Height: 11-13/16" (300 mm)
Depth: 8" (204 mm)

1 – 2

– 4

[4] Names Of Parts

2

3
4

5

AUDIO IN

6

PHONES

7
8

MINI COMPONENT SYSTEM

POWER

ON/STAND-BY

CD-DH790

CD-DH790N

1

Front panel

1. iPod Docking Station

2. Disc Tray

3. Remote Sensor

4. Timer Indicator

5. Power On/Stand-by Button

6. Audio In Jack

7. Headphone Jack

8. USB Terminal

9. Volume Control

10. FUNCTION Button

11. Disc / USB / iPod Play or Pause / Tape Play /
Tuning Up Button

12. Disc / USB / Tape Stop / Tuning Down Button

13. Disc Tray Open / Close Button

14. Cassette Compartment

VOL

FUNCTION

9

10
11

12
13

PUSH
OPEN

14

1 2 34 5

13 14

8 9 10

7

15

16

12

1

2

Display

6

11

1. MP3/WMA Folder Indicator

2. MP3/WMA Title Indicators

3. MP3 Indicator

4. WMA Indicator

5. Sleep Indicator

6. Once Timer Play Indicator

7. MP3/WMA Total Indicator

8. Daily Timer Play Indicator

9. FM Stereo Mode Indicator

10. FM Stereo Receiving Indicator

11. Tape play Indicator

12. Memory Indicator

13. Extra Bass Indicator

14. Disc/USB Repeat Play Indicator

15. Disc/USB Pause Indicator

16. Disc/USB Play Indicator

3

Speaker System

1. Tweeter

2. Woofer

3. Bass Reflex Duct

4. Speaker Wire

4

1 – 3

–2

CD-DH790N

1

22

2
3

4
5
6
7
8

9

10
11

12

CD

USB

23
24
25

26
27
28
29

30

13
14

15
16

17
18
19

20

TAPE

31
32

33
34

35

21

36

Remote control

1. Remote Control Transmitter

2. On/Stand-by Button

3. Direct Search Buttons

4. Play Mode Button

5. iPod Display (TV OUT) Button

6. Disc/USB Stop Button

7. Disc/USB Display Button

8. Bass/Treble Button

9. Volume Up or Down Buttons

10. Memory Button

11. Clear/Dimmer Button

12. Folder Button

13. Tuning Up, iPod Cursor Up Button

14. CD Track Down or Fast Reverse, Time Down Button

15. Enter Button

16. Tuning Down, iPod Cursor Down Button

17. Demo Button

18. iPod Button

19. Disc Button

20. USB Button

21. Audio In Button

22. Open/Close Button

23. iPod Menu Button

24. iPod Play/Pause Button

25. Disc/USB Play/Pause Button

26. X-Bass Button

27. Equaliser Mode Button

28. Clock/Timer Button

29. Sleep Button

30. Tuner Preset Up Button

31. CD Track Up or Fast Forward, Time Up Button

32. Tuner Preset Down Button

33. Tape Button

34. Tape Play Button

35. Tape Stop Button

36. Tuner (Band) Button

1 – 4

– 4

CD-ES700/CD-ES77CD-ES700/CD-ES77Service ManualCD-ES700/CD-ES77MarketE

CHAPTER 2. ADJUSTMENTS

[1] Mechanism Section

• Driving Force Check

Torque Meter Specified Value

Play: TW-2111 Tape 1: Over 90 g

• Torque Check

Torque Meter Specified Value

Play: TW-2111 29 to 75 g.cm
Fast Forward: TW-2231 55 to 170 g.cm
Rewind: TW-2231 55 to 170 g.cm

• Tape Speed

CD-DH790N

Test Tape Adjusting

Normal
speed

Figure 1

MTT-111 Variable

Point

Resistor in
motor.

TAPE MECHANISM

Tape Motor

Variable Resistor in motor

Specified

Value

3,000 ± 90 Hz
Speaker

Instrument

Connection

Speaker
Terminal
(Load
resistance:
6 ohms)

2 – 1

CD-DH790N

CD-ES700/CD-ES77CD-ES700/CD-ES77Service ManualCD-ES700/CD-ES77MarketE

CHAPTER 3. MECHANISM BLOCKS

[1] Caution On Disassembly

Follow the below-mentioned notes when disassembling the unit and reassembling it, to keep it safe and ensure
excellent performance:

1. Take cassette tape and compact disc out of the unit.

2. Be sure to remove the power supply plug from th e wall outlet before starting to disassemble the unit.

3. Take off nylon bands or wire holders where they need to be re moved when disassembling th e un it. After servicing
the unit, be sure to rearrange the leads where they were before disassembling.

STEP REMOVAL PROCEDURE FIGURE

.........

(A1)x5
(A2)x1

(B1)x8 1

(C1)x2 2

(D1)x1
(D2)x2

(E1)x2
(E2)x1
(E3)x1

(F1)x9 3

(G1)x2
(G2)x2
(G3)x4
(G4)x2

(H1)x4
(H2)x1

(J4)x4 4
(K1)x6

(K2)x1

(L1)x1 6

(M1)x1
(M2)x1
(M3)x1
(M4)x4

(N1)x2
(N2)x2
(N3)x1

(P1)x4
(P2)x1

(Q1)x4 9

1 Top Cabinet

Side Panel (Left/

2

Right)

iPod PWB

3

4 iPod Transit PWB

5 CD Changer unit

Rear Panel with

6

Fan motor

7 Front Panel

8Main PWB

9Power PWB

10 Tape Mechanism

11 Audio In PWB

12 Display PWB

13 CD PWB

Changer

14

Mechanism Unit

15 CD Mechanism

..........................

1. Screw

2. Flat Cable....................

2. Screw

..........................

..........................

1. Screw

..........................

1. Screw

2. Socket

1. Hook

2. Socket

3. Flat Cable

1. Screw

1. Screw

2. Flat Cable

3. Socket

4. Hook

1. Screw

2. Socket

1. Screw

1. Screw

2. Flat Cable

1. Screw

1. Knob

2. Nut

3. Washer

4. Screw

1. Screw

2. Flat Cable

3. Socket

1. Screw

.........................

...........................

..........................

.....................

...........................

..........................

...................

........................

...........................

..........................

.........................

..........................

..........................

....................

..........................

...........................

..............................

........................

..........................

..........................

....................

.........................

..........................

2. Changer Chassis

1. Screw

..........................

Note:

After removing the connector for the optical pickup from the connector,
wrap the conductive aluminium foil around the front end of the connector
so as to protect the optical pickup from electrostatic damage.

Top Cabinet

Front Panel

4
3,4
3,4

4

3, 4

4

1
3

3

3

5

6

7

8

CD Changer Unit

iPod PWB

M3 x 10mm

CD Servo PWB

Top Cabinet

(C1) x 2

Figure 2

(E3) x 1

(E2) x 1

(D1) x 1
Special Screw

iPod
Transit PWB

(A2) x 1

(D2) x 2

(G2) x 1

Front Panel

(B1) x 2

M3 x 10mm

(A1) x 1

M3 x 12mm

(A1) x 2

M3 x 12mm

Side Panel
(Right)

(B1) x 2

M3 x 10mm

Figure 1

Rear Panel

(B1) x 2

M3 x 10mm

(B1) x 2

M3 x 10mm

(A1) x 2

M3 x 12mm

Side Panel (Left)

3 – 1

Rear Panel

(F1) x 9

M3 x 10mm

PULL

(E1) x 1

(G3) x 1

Power PWB

Fan Motor

Figure 3

Hook

Main PWB

(H1) x 1

Special Screw

Hook
(E1) x 1

PULL

Lug wire

(H1) x 1

Special Screw

CD-DH790N

Hook

(G4) x 1

PULL

Power PWB

(J1) x 4
M4 x 8mm

Figure 4

(H2) x 1

(G3) x 1

(K2) x 1

(G2) x 1

(H1) x 2
M3 x 6mm

Front Panel

(G3) x 2

Front Panel

(G1) x 2
M3 x 8mm

(G4) x 1

PULL

Hook

(N3) x 1

(N2) x 1

(P1) x 4

M3 x 10mm

Figure 7

(N1) x 2

M3 x 10mm

(N2) x 1

CD PWB

Changer
Mechanism
Unit

Display PWB

Mechanism

(K1) x 6

M3 x 10mm

(M4) x 4

M2.6 x 10mm

Tap e

Figure 5

Display PWB

Lug wire

Front Panel

(M2) x 1

(M3) x 1

(M1) x 1

Figure 8

CD Mechanism

(Q1) x 4
Special

(P2) x 1

Changer
Mechanism
Unit

(L1) x 1

Special Screw

Figure 6

Audio In PWB

3 – 2

Figure 9

Changer
Mechanism
Unit

CD-DH790N

STEP PROCEDURE FIGURE

1 1. Front Panel Ass’y………(A1) X 1

Woofer

REMOVAL

10

1. Screw…….…….…….… (A2) X 4

2 Tweeter 1. Screw…….……….....….(B1) X 2 10

Speaker Box

Tweeter

(B1) x 2

M3 x 10mm

Front Panel Ass’y

(A1) x 1

Figure 10

(A2) x 4

M4 x16mm

Woofer

Screwdriver

SPEAKER UNIT

LOCKING TAB

LOCKING TAB

CAUTION:

TO REMOVE SPEAKER UNIT, PRESS THESE LOCKING TABS
TO RELEASE SPEAKER WIRES.

SPEAKER WIRE

3 – 3

-MEMO-

CD-DH790N

3 – 4

CD-DH790N

2

2

A

CHAPTER 4. DIAGRAMS

[1] Main Block Diagram

SYS_PROTECT

5.6V

+13V

Q852

L927

R
L

Q905

Q901

2

R
L

5A 1

5A 1

2

2A

2A

1.6

Figure 4-1: MAIN BLOCK DIAGRAM (1/2)

4 – 1

CD-DH790N

R
L

5A 125V

5A 125V

2

2A 125V

2A 125V

1.6A 125V

14

12

17

15

8

9

10

11

5A 125V

7

L844

ZA016AW

3

120V ~ 60Hz

Figure 4-2: MAIN BLOCK DIAGRAM (1/2)

4 – 2

CD-DH790N

[2] Servo Block Diagram

FROM

MAIN PWB

+13V

Q10 ~
Q13

T_SOL
T_MOTOR
T_PHOTO

TAPE MECHA ASSY

TAPE R_IN

TAPE L_IN

+B2

14 13

11

+B6

Y3

9

48

7

8

5

21123

T_SOLin
T_MOTOR 1
PHOTO_OUT

Y1/Y2

37

43 CD_PWR

42 CD_ACK
41 STB
40 CD_DATA

+B3

09 08

MODE36RESET

38

39

45

28

26

27

36 PIN

D1

Figure 4-3: SERVO BLOCK DIAGRAM (1/2)

4 – 3

CD-DH790N

To CD PICKUP

CNP404

27 26

08

111 CD +5V

74 CD_ACK
73 CD_DATA
72 STB

53

52

51

50

123

121

126

127

Q6

+B3

8

4

18 22

17

23

4

1

26

2

15

15 14

5

6

7

4

To CD PICK_UP

To CD LOADER

16 13 14

16 13

CNP405

CNP406

19

8

+B3

Figure 4-4: SERVO BLOCK DIAGRAM (2/2)

4 – 4

CD-DH790N

CHAPTER 5.

CIRCUIT DESCRIPTION

[1] Waveform Of Servo Circuit

1

U10 U10

2

U10

4

U10 U10

1

126

126

127

FOO

TRO

Figure 1 Figure 2

TE

14

FOO

1

3

U10

4

FOO

126

FE

13

TE

14

U10

1

5

FOO

126

DMO

123

U10 U10

Figure 3 Figure 4

LINEOUTL

6

33

U10

7

36

U10 U10

LINEOUTR

Figure 5 Figure 6

9

DM

52

U10

10

53

DP

RFO

5 – 1

[2] Voltage

IC701 IC851 IC702

PINNOVOLTAGE

(V)

1 -26.66 33 -26.68 1 5.12 1 12.13
2 -26.66 34 -29.10 2 13.03 2 12.23
3 -26.66 35 -26.68 3 18.53 3 3.79
4 -26.66 36 -21.10 4 0.00 4 2.49
5 3.15 37 -17.68 5 19.65 5 0.50
6 3.15 38 -22.10 6 10.05 6 0.50
7 3.06 39 -29.10 7 8.51 7 0.50
8 3.15 40 -24.25 8 0.50

9 3.15 41 -19.40
10 3.15 42 -26.66
11 3.15 43 -24.25
12 1.45 44 -24.57
13 1.45 45 -24.27 1 11.05
14 0.00 46 -19.43 2 0.69 1 5.10
15 -17.50 47 -26.68 3 5.70 2 5.06
16 -29.09 48 -26.68 3 4.94
17 -29.10 49 -29.10 4 0.00
18 -29.10 50 -22.10
19 -29.10 51 -22.10 6 5.06
20 -29.10 52 3.15 7 5.09
21 -29.10 53 -29.10 1 5.12 8 10.04
22 -26.90 54 -29.10 2 5.12
23 -15.26 55 -29.10 3 3.29
24 -29.25 56 -29.10 4 1.92
25 -29.10 57 -26.68 5 0.00
26 -29.10 58 -26.68 6 0.00
27 -19.75 59 -26.68 7 0.00 1 2.02
28 -29.10 60 -26.68 8 0.00 2 2.02
29 -19.70 61 -26.68 3 2.02
30 -21.84 62 -26.68 4 0.00
31 -19.55 63 -26.68
32 -15.23 64 -26.68 6 2.02

PINNOVOLTAGE

(V)

1 2.53 13 -24.48 6 2.52 1 0.50

2 0.00 14 0.00 7 0.00 2 5.70

3 2.44 15 11.45 8 5.12 3 3.16

4 24.15 16 24.35 9 0.00 4 0.00

5 0.00 17 -24.29 10 2.54 5 3.17

6 -24.08 18 -24.15 11 2.57 6 5.09

7 -15.95 19 0.00 12 5.12 7 5.70

8 24.17 20 24.09 13 0.00 8 3.17

9 11.46 21 0.00 14 5.12
10 0.00 22 0.00
11 -24.38 23 2.67
12 -12.10

PINNOVOLTAGE

IC901

PINNOVOLTAGE

(V)

(V)

PINNOVOLTAGE

(V)

IC852

PINNOVOLTAGE

(V)

IC853

PINNOVOLTAGE

(V)

IC902

PINNOVOLTAGE

(V)

1 0.00 8 5.12
2 5.12
3 2.52
4 2.57
5 2.42

PINNOVOLTAGE

IC604

PINNOVOLTAGE

5 4.94

PINNOVOLTAGE

IC603

PINNOVOLTAGE

5 2.02

7 2.04

IC855

PINNOVOLTAGE

IC856

PINNOVOLTAGE

1 14.43
2 1.08
3 6.05

(V)

(V)

(V)

(V)

(V)

(V)

CD-DH790N

5 – 2

CD-DH790N

PINNOVOLTAGE

10 3.16 26 3.16 42 3.17 58 3.17
11 0.00 27 35m 43 3.13 59 0.00
12 0.00 28 3.20 44 37m 60 3.20
13 0.00 29 35m 45 3.15 61 3.20
14 3.21 30 3.15 46 3.17 62 2.16
15 1.50 31 3.16 47 3.17 63 17m
16 2.94 32 32m 48 0.00 64 2.97

PINNOVOLTAGE

PINNOVOLTAGE

10 3.17 2 5.05 2 2.19 22 0.00
11 3.18 3 5.05 3 3.30 23 1.58
12 0.00 4 0.00 4 0.00 24 5.81
13 0.77 5 5.05 5 0.00 25 0.00
14 0.77 6 5.05 6 0.41 26 1.58
15 0.00 7 5.05 7 3.30 27 1.58
16 0.00 8 10.01 8 3.34 28 5.83
17 0.00
18 0.00
19 3.17
20 0.53

U1

PINNOVOLTAGE

(V)

1 2.93 17 34m 33 36m 49 3.14
2 38m 18 34m 34 33m 50 3.20
3 3.15 19 3.15 35 3.15 51 3.20
4 0.75 20 3.16 36 1.17 52 3.15
5 1.14 21 35m 37 3.15 53 19m
6 3.14 22 3.55 38 3.15 54 3.15
7 1.63 23 35m 39 3.15 55 3.15
8 0.00 24 3.54 40 3.17 56 0.00
9 1.56 25 3.15 41 3.15 57 3.15

U2 U3 U12

PINNOVOLTAGE

(V)

1 0.00 1 4.04 17 3.15 1 1.58
2 0.00 2 4.02 18 9.15 2 5.12
3 0.00 3 4.02 19 9.15 3 1.79
4 0.00 4 4.02 20 4.12 4 1.58
5 3.15 5 4.02 21 4.04 5 1.24
6 3.15 6 4.04 22 4.04 6 0.00
7 0.00 7 4.02 23 4.04 7 0.00
8 3.17 8 4.04 24 4.05 8 5.98

9 4.04 25 4.03 9 0.00

U6

(V)

1 0.53 13 0.00 29 4.02 13 3.01
2 0.00 14 0.00 30 4.03 14 2.99
3 0.00 15 3.15 31 4.03 15 2.93
4 0.00 16 3.15 32 4.03 16 2.93
5 3.14 17 2.93
6 3.14
7 3.04 19 5.80
8 3.03 20 0.98
9 1.46 1 5.05 1 0.00 21 1.60

10 0.00 26 4.02 10 0.00
11 4.04 27 4.05 11 3.01
12 4.03 28 4.03 12 3.01

PINNOVOLTAGE

(V)

(V)

U8 U11

(V)

PINNOVOLTAGE

(V)

PINNOVOLTAGE

(V)

PINNOVOLTAGE

(V)

PINNOVOLTAGE

(V)

PINNOVOLTAGE

(V)

18 2.96

5 – 3

U10

PINNOVOLTAGE

(V)
1 3.38 33 1.53 65 1.23 97 NC
2 1.79 34 1.53 66 NC 98 NC
3 1.58 35 1.53 67 NC 99 0.71
4 1.60 36 1.53 68 NC 100 NC
5 1.60 37 0.00 69 NC 101 NC
6 1.60 38 3.34 70 141m 102 NC
7 1.60 39 NC 71 0.00 103 1.25
8 3.39 40 NC 72 NC 104 0.72
9 1.59 41 NC 73 NC 105 0.72

10 1.19 42 NC 74 NC 106 NC
11 0.00 43 NC 75 NC 107 NC
12 1.12 44 NC 76 NC 108 NC
13 1.18 45 0.77 77 NC 109 NC
14 1.38 46 1.53 78 NC 110 0.00
15 0.81 47 0.77 79 NC 111 5.80
16 3.34 48 1.53 80 NC 112 0.00
17 3.34 49 1.72 81 NC 113 3.34
18 1.79 50 2.11 82 NC 114 0.00
19 1.67 51 2.08 83 NC 115 1.77
20 2.31 52 30.4m 84 0.00 116 3.34
21 0.00 53 2.82 85 3.34 117 NC
22 0.00 54 3.34 86 0.72 118 NC
23 3.33 55 0.00 87 NC 119 NC
24 1.78 56 0.00 88 NC 120 1.58
25 3.34 57 3.34 89 NC 121 1.57
26 1.27 58 0.00 90 NC 122 3.34
27 0.72 59 2.19 91 NC 123 1.57
28 0.00 60 0.00 92 1.30 124 0.00
29 1.77 61 0.41 93 1.13 125 NC
30 0.00 62 3.34 94 0.71 126 1.57
31 1.53 63 3.34 95 0.71 127 1.57
32 1.53 64 1.22 96 NC 128 233m

PIN
NO

VOLTAGE

(V)

PIN
NO

VOLTAGE

(V)

PIN

NO

VOLTAGE

(V)

CD-DH790N

IC401

PINNOVOLTAGE

(V)
1 0.00 9 0.00 17 25.80m
2 0.00 10 200.10m 18 0.00
3 0.00 11 0.00 19 0.00
4 0.78 12 0.00 20 2.80
5 2.79 13 6.87 21 0.77
6 0.00 14 4.13 22 0.00
7 0.00 15 0.00 23 0.00
8 25.80m 16 0.00 24 0.00

PINNOVOLTAGE

(V)

PINNOVOLTAGE

(V)

5 – 4

CD-DH790N

-MEMO-

5 – 5

CD-DH790N

CHAPTER 6. CIRCUIT SCHEMATICS AND PARTS LAYOUT

[1] Notes On Schematic Diagram

• Resistor:
To differentiate the units of resistors, such symbol as K and M are
used: the symbol K means 1000 ohm and the symbol M means
1000 kohm and the resistor without any symbol is ohm-type resis­tor. Besides, the one with “Fusible” is a fuse type.

• Capacitor:
To indicate the unit of capacitor, a symbol P is used: this symbol P
means pico-farad and the unit of the capacitor without such a sym­bol is microfarad. As to electrolytic capacitor, the expression
"capacitance/withstand voltage is used".
(CH), (TH), (RH), (UJ): Temperature compensation
(ML): Mylar type
(P.P.): Polypropylene type

REF. NO

VR701 VOLUME MAX -- MIN

SW701 ON/STAND-BY ON -- OFF

SW702 FUNCTION ON -- OFF

SW703 DISC/USB/TAPE STOP/TUNING DOWN ON -- OFF

SW704 DISC/USB/iPod PLAY or PAUSE/

TAPE PLAY/TUNING UP

SW705 OPEN/CLOSE ON -- OFF

DESCRIPTION POSITION

ON -- OFF

• Schematic diagram and Wiring Side of P.W.Board for this model are
subject to change for improvement without prior notice.

• The indicated voltage in each section is the one measured by Digi­tal Multimeter between such a section and the chassis with no sig­nal given.

1. In the tuner section,
indicates AM
indicates FM stereo

2. In the main section, a tape is being playback.

3. In the power section, a tape is being playback.

4. In the CD section, the CD is stopped.

Parts marked with “ ” ( ) are important for main-

•
taining the safety of the set. Be sure to replace these parts with

specified ones for maintaining the safety and performance of the
set.

[2] Ty p es Of Transistor And LED

FRONT

VIEW

ECB
(S)(G)(D)
(1)(2)(3)

S8550
KTA1274Y
S8050
KTC3199
KTA1266
KTC3203Y

FRONT

VIEW

BCE

B772
KIA7805A
050N60P

(3)

(1)

B

E

TOP

VIEW

KRA102S
KRC107
KRC104S
H1A
KTA1504GR
KTC3875GR
KRA107S

1

TDA8920CJ

FRONT

VIEW

C

(2)

TOP VIEW

23

1N4004
DRL204F
MA 111

FRONT

VIEW

AC AC -+

10XB60F

TOP VIEW

FRONT
VIEW

HSS4148

343VC3F

TOP VIEW

BCE

HD

6 – 1

CD-DH790N

A

[3] Schematic Diagram

A

FM SIGNAL
CD SIGNAL
AUDIO SIGNAL
iPod SIGNAL

B

C

TO SERVO PWB

D

HEADPHONE

MAIN PWB-

E

F

G

H

1

23456

Figure 6-1: MAIN SCHEMATIC DIAGRAM (1/6)

6 – 2

IN PWB-A1

CD-DH790N

C992

100P

7

8 9 10 11 12

47P

47P

47P

Figure 6-2: MAIN SCHEMATIC DIAGRAM (2/6)

6 – 3

CD-DH790N

13

C988 0.1uF

C989 0.1uF

0.01u

14 15 16 17 18

Figure 6-3: MAIN SCHEMATIC DIAGRAM (3/6)

6 – 4

TO

SPEAKER SYSTEM

CD-DH790N

A

B

C

TO SERVO PWB

D

C695

0.1u

FB691

E

LN-0061

F

G

SIDE ENTRY

H

1

23456

Figure 6-4: MAIN SCHEMATIC DIAGRAM (4/6)

6 – 5

CD-DH790N

C992

100P

47P

47P

47P

TO SERVO PWB

7

8 9 10 11 12

Figure 6-5: MAIN SCHEMATIC DIAGRAM (5/6)

6 – 6