DOWNLOAD Sony HCD-EC68USB / MHC-EC68USB Service Manual ↓ Size: 4.3 MB | Pages: 64 in PDF or view online for FREE

2008F05-1

© 

2008.06

•  HCD-EC68USB is the amplifi er, USB, CD player 

and tuner section in MHC-EC68USB.

Model Name Using Similar Mechanism

NEW

Mechanism Type

CDM88A-K6BD91UR-WOD

Base Unit Name

BU-K6BD91UR-WOD

Optical Pick-up Block Name

KSM-213DCP

European model:
Power output (rated):

70 W + 70 W (at 6 Ω, 1 kHz,
1% THD)

RMS output power (reference):

90 W + 90 W (per channel at 6 Ω, 
1 kHz, 10% THD)

Other models:

220, 240 V, 50/60 Hz
Power output (rated):

50 W + 50 W (at 6 Ω, 1 kHz,
1% THD)

RMS output power (reference):

70 W + 70 W (per channel at 6 Ω, 
1 kHz, 10% THD)

AUDIO IN (stereo mini jack):
Sensitivity 800 mV, impedance 22 kilohms

 (USB) port: Type A

PHONES (stereo mini jack): accepts
headphones with an impedance of 8 Ω or
more
SPEAKER: impedance
6 Ω

Supported bit rate

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

Sampling frequencies

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

Transfer speed

Full-Speed

Supported USB device

Mass Storage Class

Maximum current

500 mA

System: Compact disc and digital audio
system
Laser: Semiconductor laser (λ=770 − 
810 nm)
Emission duration: continuous
Frequency response: 20 Hz − 20 kHz
Signal-to-noise ratio: More than 90 dB
Dynamic range: More than 88 dB

FM stereo, FM/AM superheterodyne tuner
Antenna:

FM lead antenna
AM loop antenna

FM tuner section:

Tuning range:

87.5 − 108.0 MHz (50 kHz step)

Intermediate frequency: 10.7 MHz

AM tuner section:

Tuning range
European model:

531 − 1,602 kHz
(with 9 kHz tuning interval)

Other models:

530 − 1,710 kHz
(with 10 kHz tuning interval)
531 − 1,710 kHz
(with 9 kHz tuning interval)

Intermediate frequency: 450 kHz

Power requirements
European model:
AC 230 V, 50/60 Hz
Mexican model: AC 127 V, 60 Hz
Argentine model: AC 220 V, 50/60 Hz
Other models: AC 120, 220 or 230 – 240 V,
50/60 Hz, adjustable with voltage selector

Power consumption
European model:

130 W
0.5 W (in Power Saving Mode)

Other models: 110 W
Dimensions (w/h/d) (excl. speakers)

Approx. 200 × 306 × 415 mm

Mass (excl. speakers)

European model:
6.0 kg
Other models:
5.6 kg

change without notice.

  .............................................   3

  ..................................................................   7

3-1. Disassembly 

Flow 

...........................................................   8

3-2. Side 

Panel 

(L)/(R) 

...........................................................   9

3-3. Panel 

(Top) 

......................................................................   9

3-4. MAIN 

Board 

...................................................................  10

3-5.  Front Panel Block ...........................................................   10
3-6.  Back Panel Block ............................................................   11
3-7.  3 CD Mechanism Block ..................................................   11
3-8. Base 

Unit 

.........................................................................  12

3-9.  OP Base Assy (KSM-213D) ...........................................   12
3-10. Belt (DLM3A) ................................................................   13

TEST  MODE 

 ............................................................   14

ADJUSTMENTS 

 ........................   18

6-1.  Block Diagram - CD SERVO, TUNER Section - ...........   20
6-2.  Block Diagram - USB Section - .....................................   21
6-3.  Block Diagram - MAIN Section - ...................................   22
6-4.  Printed Wiring Board - CD Board - ................................   24
6-5.  Schematic Diagram - CD Board - ...................................   25
6-6.  Printed Wiring Boards - USB Section - ..........................   26
6-7.  Schematic Diagram - USB Section - ..............................   27
6-8. Printed 

Wiring 

Board 

 

- MAIN Board (Suffi x-12/-13) - .....................................   28

6-9.  Printed Wiring Board - MAIN Board (Suffi x-14) - ........   29
6-10.  Schematic Diagram - MAIN Board (1/2) - .....................   30
6-11.  Schematic Diagram - MAIN Board (2/2) - .....................   31
6-12.  Printed Wiring Board - LOW AMP Board - ...................   32
6-13.  Schematic Diagram - LOW AMP Board - ......................   32
6-14.  Printed Wiring Boards - KEY Section - ..........................   33
6-15.  Schematic Diagram - KEY Section - ..............................   33
6-16.  Printed Wiring Board - PANEL Board (Suffi x-12) - ......   34
6-17.  Printed Wiring Board - PANEL Board (Suffi x-13) - ......   35
6-18.  Printed Wiring Board - PANEL Board (Suffi x-14) - ......   36
6-19.  Schematic Diagram - PANEL Board - ............................   37
6-20.  Printed Wiring Board - PT Board - .................................   38
6-21.  Schematic Diagram - PT Board - ....................................   39

7-1. Panel 

Section 

...................................................................  48

7-2.  Front Panel Section .........................................................   49
7-3. Chassis 

Section 

...............................................................  50

7-4. Main 

Section 

...................................................................  51

7-5.  3 CD Mechanism Section 
 (CDM88A-K6BD91UR-WOD) 

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

52

  ..............................   53

Note: Refer to “Suffi x-14” for DIAGRAMS of 120V AC area in E 

model.

Notes on chip component replacement
• 

Never reuse a disconnected chip component.

• 

Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.

Flexible Circuit Board Repairing
• 

Keep the temperature of soldering iron around 270 °C during 
repairing.

• 

Do not touch the soldering iron on the same conductor of the 
circuit board (within 3 times).

• 

Be careful not to apply force on the conductor when soldering 
or unsoldering.

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

CAUTION
Use of controls or adjustments or performance of procedures other than 
those specifi ed herein may result in hazardous radiation exposure.

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 

The laser diode in the optical pick-up block may suffer electrostat-
ic 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 lead-
free 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)

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 viscou-s (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.

RELEASING  THE  DISC  TRAY  LOCK
The disc tray lock function for the antitheft of an demonstration 
disc in the store is equipped.

Releasing Procedure:
1. Press 

[

?/1

] button to turn the power on.

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

x

] button, press the [

Z

] button for more 5 

seconds).

4.  The message “UNLOCKED” is displayed and the disc tray is 

unlocked.

Note: When 

“

LOCKED

”

 is displayed, the slot lock is not released by 

turning power on/off with the

 [

?/1

]

 button.

AEP model

3-398-095-0[]

120V AC area in E, Chilean and Peruvian 
models

3-398-096-0[]

Mexican model

3-398-097-0[]

Argentina model

3-398-098-0[]