HCD-FX250 - Sony Audio Service Manual (repair manual)

2010D05-1

© 

2010.04

•  HCD-FX250 is the amplifier, CD player 

and tuner in CMT-FX250.

Model Name Using Similar Mechanism

NEW

Base Unit Name

BU-D1BD73

Optical Pick-up Block Name

DA11MMVGP

 MPEG Layer-3 audio coding technology and patents 

licensed from Fraunhofer IIS and Thomson.

 All other trademarks and registered trademarks are of 

their respective holders. In this manual, 

TM

 and 

®

 marks 

are not specified.

DIN power output (rated): 4 watts + 4 watts (4 ohms at 1 kHz, DIN)
Continuous RMS power output (reference): 5 watts + 5 watts (4 ohms at 
1 kHz, 10% THD)
Music power output (reference): 9 watts + 9 watts

AUDIO IN (stereo mini jack): Sensitivity 550 mV, impedance 50 kilohms

PHONES (stereo mini jack): Accepts headphones with an impedance of 
8 ohms or more
SPEAKERS: Accepts impedance of 4 ohms

CD player section
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
Tuner section
FM stereo, DAB/FM superheterodyne tuner
Antenna: DAB/FM lead antenna
DAB tuner section:

Frequency range*
Band-III: 174.928 (5A) MHz   239.200 (13F) MHz
* For details, see “DAB frequency table” below.

DAB frequency table (Band-III)

174.928 MHz

5A

209.936 MHz

10A

176.640 MHz

5B

211.648 MHz

10B

178.352 MHz

5C

213.360 MHz

10C

180.064 MHz

5D

215.072 MHz

10D

181.936 MHz

6A

216.928 MHz

11A

183.648 MHz

6B

218.640 MHz

11B

185.360 MHz

6C

220.352 MHz

11C

187.072 MHz

6D

222.064 MHz

11D

188.928 MHz

7A

223.936 MHz

12A

190.640 MHz

7B

225.648 MHz

12B

192.352 MHz

7C

227.360 MHz

12C

194.064 MHz

7D

229.072 MHz

12D

195.936 MHz

8A

230.784 MHz

13A

197.648 MHz

8B

232.496 MHz

13B

199.360 MHz

8C

234.208 MHz

13C

201.072 MHz

8D

235.776 MHz

13D

202.928 MHz

9A

237.488 MHz

13E

204.640 MHz

9B

239.200 MHz

13F

206.352 MHz

9C

208.064 MHz

9D

FM tuner section:

Tuning range: 87.5 MHz   108.0 MHz (50 kHz step)
Intermediate frequency: 2.048 MHz

General
Power requirements: AC 230 V, 50/60 Hz
Power consumption: 18 watts
Dimensions (W/H/D) (excl. speakers):

Approx. 158 mm × 240 mm × 225.5 mm

Mass (excl. speakers): Approx. 2.2 kg

Design and specifications are subject to change without notice.

 Standby power consumption: 0.5 W
 Halogenated flame retardants are not used in the certain printed 

wiring boards.

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

2-1. Disassembly 

Flow 

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

2-2.  Panel (Rear) Block ..........................................................   4
2-3.  Top Panel Block ..............................................................   5
2-4.  Front Panel Block ...........................................................   5
2-5. Knob 

(VOL) 

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

2-6.  Module (DAB Tuner) Block, MAIN Board ....................   6
2-7.  Base Unit (BU-D1BD73) ................................................   7
2-8.  Optical Pick-up Block (DA11MMVGP) ........................   7

TEST  MODE 

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

8

ELECTRICAL  CHECK 

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

9

5-1.  Block Diagram - CD, TUNER Section - ........................   10
5-2. Block 

Diagram 

- OUTPUT, PANEL, POWER SUPPLY Section - .........   11

5-3.  Printed Wiring Board - BD73 Board - ............................   14
5-4.  Schematic Diagram - BD73 Board - ...............................   15
5-5.  Schematic Diagram - MAIN Section (1/2) - ...................   16
5-6.  Schematic Diagram - MAIN Section (2/2) - ...................   17
5-7.  Printed Wiring Boards - MAIN Section - .......................   18
5-8.  Printed Wiring Board - PANEL Board - .........................   19
5-9.  Schematic Diagram - PANEL Board (1/2) - ...................   20
5-10.  Schematic Diagram - PANEL Board (2/2) - ...................   21
5-11.  Printed Wiring Board - PT Board - .................................   22
5-12.  Schematic Diagram - PT Board - ....................................   22

6-1. Overall 

Section 

...............................................................  26

6-2.  Top Panel Section ...........................................................   27
6-3.  Front Panel Section .........................................................   28
6-4. Chassis 

Section 

...............................................................  29

  ..............................   30

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  

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 or bottom exterior.

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.

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.

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 SW880. (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 SW880 as shown in Fig.1.

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

damaged.

  3.  Check the object lens for confi rming normal emission of the 

laser diode. If not emitting, there is a trouble in the automatic 
power control circuit 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.

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.

CAPACITOR  ELECTRICAL  DISCHARGE  PROCESSING
When checking the board, the electrical discharge is necessary for the electric shock prevention.
Connect the resistors referring to the fi gure below.
•   PT board (C905) 
•   MAIN board (C903, C904)
Both ends of respective capacitors.

:/2 W

:/2 W

:/2 W

• 

This set can be disassembled in the order shown below.

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

Note: This illustration sees the set from rear side.

3

2 two screws

u 10)

4 panel (rear) block

1 three screws

u 8)

2 four screws

u 10)