DOWNLOAD Sony HCD-BX20I / HCD-BX50BTI Service Manual ↓ Size: 4.94 MB | Pages: 70 in PDF or view online for FREE

2013B33-1

© 

2013.02

Model Name Using Similar Mechanism

HCD-BX5BT/EC68

Base Unit Name

BU-K6BD90-WOD

Optical Pick-up Block Name

KSM-213DCP

•  HCD-BX20i is the amplifi er, CD player, tuner and 

iPod section in CMT-BX20i.

•  HCD-BX50BTi is the amplifi er, bluetooth, CD player, 

tuner and iPod section in CMT-BX50BTi.

Photo: HCD-BX20i

– Continued on next page –

• The Bluetooth word mark and logos are owned by the Bluetooth SIG, Inc. 

and any use of such marks by Sony Corporation is under license. Other 
trademarks and trade names are those of their respective owners.

• MPEG Layer-3 audio coding technology and patents licensed from 

Fraunhofer IIS and Thomson.

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

AUDIO POWER SPECIFICATIONS
POWER OUTPUT AND TOTAL HARMONIC DISTORTION:
(The United States model only)
With 6 ohm loads, both channels driven, from 120 – 

10,000Hz; rated 25 watts 

per channel minimum RMS power, with no more than 10% total harmonic 
distortion from 250 milliwatts to rated output.

DIN power output (rated): 
18 + 18 W (6 ohms at 1 kHz, DIN) 
Continuous RMS power output (reference): 25 + 25 W (6 ohms at 1 kHz, 
10% THD)

Inputs

Inputs

AUDIO IN (stereo mini jack): voltage 250 mV, impedance 47 kilohms

Outputs

Outputs

PHONES (stereo mini jack): accepts headphones of 8 ohms or more
SPEAKER: accepts impedance of 6 to 16 ohms

System: Compact disc and digital audio system
Laser Diode Properties

Emission Duration: Continuous
Laser Output*: Less than 44.6μW
* This 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

Continuous RMS power output (reference): 25 + 25 watts (6 ohms at 
1 kHz, 10% THD)

AUDIO IN (stereo mini jack): voltage250mV, impedance 47 kilohms

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

Communication system: Bluetooth Standard version 2.0
Output: Bluetooth Standard Power Class 2

Maximum communication range: Line of sight approx. 10 m

1)

Frequency band: 2.4 GHz band (2.4000 GHz – 2.4835GHz)

Modulation method: FHSS

Compatible Bluetooth profiles 

2)

:

A2DP (Advanced Audio Distribution Profile)

AVRCP (Audio Video Remote Control Profile)

1)

The actual range will vary depending on factors such as obstacles 
between devices, magnetic filds around a microwave oven, static 
electricity, reception sensitivity, antenna’s performance, operating 
system, software application, etc.

2)

Bluetooth standard profiles indicate the purpose of Bluetooth 
communication between devices.

Supported codecs:

Receive: SBC (Sub Band Codec), MP3
Transmit: SBC (Sub Band Codec)

DIN power output (rated): 
18 + 18 W (6 ohms at 1 kHz, DIN) 
Continuous RMS power output (reference): 25 + 25 W (6 ohms at 1 kHz, 
10% THD)
Music power output (reference): 38 + 38 W (6 ohms at 1 kHz, 10% THD)

Inputs

AUDIO IN (stereo mini jack): voltage 250 mV, impedance 47 kilohms

Outputs

PHONES (stereo mini jack): accepts headphones of 8 ohms or more
SPEAKER: accepts impedance of 6 to 16 ohms

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.

0 OR  DOTTED  LINE  

0 ON  THE  SCHEMATIC  DIAGRAMS  AND  IN  

0  SUR  

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

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

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FM tuner section:

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AM tuner section:

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Tuning range: 531   1,602 kHz (with 9 kHz tuning interval)

  .............................................   4

  ..................................................................   6

3-1. Disassembly 

Flow 

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

3-2.  Panel (Side L/R) ..............................................................   11
3-3.  Top Panel Block ..............................................................   11
3-4.  TOP KEY Board, IP Board, Panel Top (IP) ....................   12
3-5.  Front Panel Block ...........................................................   12
3-6.  Rear Panel Block ............................................................   13
3-7. Panel 

(Rear) 

....................................................................  13

3-8.  AMP Board Block ...........................................................   14
3-9.  POWER Board Block .....................................................   14
3-10. MAIN Board ...................................................................   15
3-11.  Loading Mechanism Block .............................................   15
3-12. Base Unit .........................................................................   16
3-13. Belt ..................................................................................   16
3-14.  OP Base Assy (KSM-213D) ...........................................   17

TEST  MODE 

 ............................................................   18

ELECTRICAL  CHECKS 

 ......................................   20

6-1.  Block Diagram - CD SERVO Section - ..........................   21
6-2. Block 

Diagram 

 

- iPod, TUNER, BLUETOOTH Section - ......................   22

6-3.  Block Diagram - MAIN Section - ...................................   23
6-4. Block 

Diagram 

 

- PANEL, POWER SUPPLY Section - ...........................   24

6-5.  Printed Wiring Boards - CD Section - ............................   26
6-6.  Schematic Diagram - CD Board - ...................................   27
6-7. Printed 

Wiring 

Boards 

 

- BLUETOOTH Section (BX50BTi) - ............................   28

6-8. Schematic 

Diagram 

 

- BLUETOOTH Section (BX50BTi) - ............................   29

6-9.  Printed Wiring Board - IP Board - ..................................   30
6-10.  Schematic Diagram - IP Board - .....................................   31
6-11.  Printed Wiring Boards - MAIN Section - .......................   32
6-12.  Schematic Diagram - MAIN Section (1/3) - ...................   33
6-13.  Schematic Diagram - MAIN Section (2/3) - ...................   34
6-14.  Schematic Diagram - MAIN Section (3/3) - ...................   35
6-15. Printed Wiring Boards 
 

- HEADPHONE/AMP Section - .....................................   36

6-16.  Schematic Diagram - HEADPHONE/AMP Section - ....   37
6-17.  Printed Wiring Boards - PANEL Section - .....................   38
6-18.  Schematic Diagram - PANEL Section - ..........................   39
6-19.  Printed Wiring Board - POWER Board - ........................   40
6-20.  Schematic Diagram - POWER Board - ..........................   41

7-1. Panel 

Section 

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

7-2.  Top Panel Section ...........................................................   51
7-3.  Front Panel Section .........................................................   52
7-4.  MAIN Board Section ......................................................   53
7-5.  POWER Board Section ...................................................   54
7-6.  Loading Mechanism Section ..........................................   55
7-7.  Base Unit Section (BU-K6BD90-WOD)  .......................   56

  ..............................   57

SAFETY  CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs, 
screws, and all other exposed metal parts for AC leakage.
Check leakage as described below.

LEAKAGE  TEST
The AC leakage from any exposed metal part to earth ground and 
from all exposed metal parts to any exposed metal part having a 
return to chassis, must not exceed 0.5 mA (500 microamperes.). 
Leakage current can be measured by any one of three methods.
1.  A commercial leakage tester, such as the Simpson 229 or RCA 

WT-540A. Follow the manufacturers’ instructions to use these 
instruments.

2.  A battery-operated AC milliammeter. The Data Precision 245 

digital multimeter is suitable for this job.

3.  Measuring the voltage drop across a resistor by means of a 

VOM or battery-operated AC voltmeter. The “limit” indication 
is 0.75 V, so analog meters must have an accurate low-voltage 
scale. The Simpson 250 and Sanwa SH-63Trd are examples 
of a passive VOM that is suitable. Nearly all battery operated 
digital multimeters that have a 2 V AC range are suitable.  (See 
Fig. A)

The laser diode in the optical pick-up block may suffer electro-
static 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 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.

ANTITHEFT  UNLOCK  MODE
Procedure:
1.  Press the [

?/1

] button to turn the power on.

2.  Press the [FUNCTION] button to select “CD”.
3.  Press two buttons of [

x/

CANCEL] and [

A

] for 5 seconds.

4.  The message “UNLOCKED” is displayed on the fl uorescent 

indicator tube and the disc tray is unlocked.

Note:  When “LOCKED” is displayed, the tray lock is not released by 

turning power on/off with the [

?/1] button.

NOTE  OF  REPLACING  THE  IC904  ON  THE  BT BOARD
IC904 on the BT board cannot exchange with single. When IC904 
on the BT board is damaged, exchange the entire mounted board.

HCD-BX20i: US model

3-293-462-0

[]

HCD-BX20i: Canadian model

3-293-463-0

[]

HCD-BX50BTi: US model

3-293-464-0

[]

HCD-BX50BTi: Canadian model

3-293-465-0

[]

HCD-BX20i: Australian model

3-295-838-0

[]

HCD-BX20i: Singapore model

3-296-979-0

[]

HCD-BX20i: AEP model

4-154-084-0

[]