MEX-BT3800U, MEX-BT3807U, MEX-BT3850U, MEX-BT38UW - Sony Car Audio Service Manual (repair manual)

2009K0500-1

© 

2009.11

Model Name Using Similar Mechanism

MEX-BT3700U/BT3750U/BT4700U

CD Mechanism Type

MG-101Z-188//Q

Optical Pick-up Name

DAX-25A

Photo: MEX-BT3800U

FM
Tuning range: 87.5 – 107.9 MHz
Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 150 kHz
Usable sensitivity: 10 dBf
Selectivity: 75 dB at 400 kHz
Signal-to-noise ratio: 70 dB (mono)
Separation: 40 dB at 1 kHz
Frequency response: 20 – 15,000 Hz
AM
Tuning range: 530 – 1,710 kHz
Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 25 kHz
Sensitivity: 26 μV

FM
Tuning range: 87.5 – 108.0 MHz
Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 150 kHz
Usable sensitivity: 10 dBf
Selectivity: 75 dB at 400 kHz
Signal-to-noise ratio: 70 dB (mono)
Separation: 40 dB at 1 kHz
Frequency response: 20 – 15,000 Hz
MW/LW
Tuning range: 

MW: 531 – 1,602 kHz
LW: 153 – 279 kHz

Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 25 kHz
Sensitivity: MW: 26 μV, LW: 45 μV

87.5 – 108.0 MHz (at 50 kHz step)
87.5 – 107.9 MHz (at 200 kHz step)

FM tuning interval: 50 kHz/200 kHz switchable
Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 150 kHz
Usable sensitivity: 10 dBf
Selectivity: 75 dB at 400 kHz
Signal-to-noise ratio: 70 dB (mono)
Separation: 40 dB at 1 kHz
Frequency response: 20 – 15,000 Hz
AM
Tuning range: 

531 – 1,602 kHz (at 9 kHz step)
530 – 1,710 kHz (at 10 kHz step)

AM tuning interval: 9 kHz/10 kHz switchable
Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 25 kHz
Sensitivity: 26 μV

Signal-to-noise ratio: 120 dB
Frequency response: 10 – 20,000 Hz
Wow and flutter: Below measurable limit

Interface: USB (Full-speed)
Maximum current: 500 mA

Bluetooth Standard version 2.0

Bluetooth Standard Power Class 2 (Max. +4 dBm)

Line of sight approx. 10 m (33 ft)*

1

2.4 GHz band (2.4000 – 2.4835 GHz)

Modulation method: FHSS
Compatible Bluetooth Profiles*

2

A2DP (Advanced Audio Distribution Profile)
AVRCP (Audio Video Remote Control Profile)
HFP (Handsfree Profile) 1.5
HSP (Headset Profile)

*1 The actual range will vary depending on factors 

*2 Bluetooth standard profiles indicate the purpose of 

Output: Speaker outputs (sure seal connectors)
Speaker impedance: 4 – 8 ohms
Maximum power output: 52 W 

u 4 (at 4 ohms)

Outputs: 

Audio outputs terminal (front/rear)
Subwoofer output terminal (mono)
Power antenna (aerial) relay control terminal
Power amplifier control terminal

Inputs: 

BUS control input terminal
BUS audio input terminal
Telephone ATT control terminal
Remote controller input terminal
Antenna (aerial) input terminal
MIC input terminal
AUX input jack (stereo mini jack)
USB signal input connector

Tone controls: 

Low: ±10 dB at 60 Hz (XPLOD)
Mid: ±10 dB at 1 kHz (XPLOD)
High: ±10 dB at 10 kHz (XPLOD)

Power requirements: 12 V DC car battery 

(negative ground (earth))

Dimensions: Approx. 178 

u 50 u 179 mm 

(7

1

/

8

 

u 2 u 7

1

/

8

 in) (w/h/d)

Mounting dimensions: Approx. 182 

u 53 u 162 mm 

(7

1

/

4

 

u 2

1

/

8

 

u 6

1

/

2

 in) (w/h/d)

Mass: Approx. 1.2 kg (2 lb 11 oz)
Supplied accessories: 

Card remote commander: RM-X304 
Parts for installation and connections (1 set)

CEA2006 Standard
Power Output: 17 Watts RMS 
4 Ohms < 1% THD+N 
SN Ratio: 82 dBA 
(reference: 1 Watt into 4 Ohms)

4 at 

87.5 – 108.0 MHz (at 50 kHz step)

Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 150 kHz
Usable sensitivity: 10 dBf
Selectivity: 75 dB at 400 kHz
Signal-to-noise ratio: 70 dB (mono)
Separation: 40 dB at 1 kHz
Frequency response: 20 – 15,000 Hz
AM
Tuning range: 

531 – 1,602 kHz (at 9 kHz step)

Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 25 kHz
Sensitivity: 26 μV

)0)0 87.5 – 108.0 MHzDWN+]VWHS
)0±0+]DWN+]VWHS
Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 150 kHz
Usable sensitivity: 10 dBf
Selectivity: 75 dB at 400 kHz
Signal-to-noise ratio: 70 dB (mono)
Separation: 40 dB at 1 kHz
Frequency response: 20 – 15,000 Hz
MW/LW
Tuning range: 

MW: 531 – 1,602 kHz
LW: 153 – 279 kHz

Antenna (aerial) terminal: 

External antenna (aerial) connector

Intermediate frequency: 25 kHz
Sensitivity: MW: 26 μV, LW: 45 μV

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.

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 

LES  COMPOSANTS  IDENTIFIÉS  PAR  UNE  MARQUE  0  SUR  
LES  DIAGRAMMES  SCHÉMATIQUES  ET  LA  LISTE  DES  
PIÈCES  SONT  CRITIQUES  POUR  LA  SÉCURITÉ  DE  FONC-
TIONNEMENT.  NE  REMPLACER  CES  COMPOSANTS  QUE  
PAR  DES  PIÈCES  SONY  DONT  LES  NUMÉROS  SONT  DON-
NÉS  DANS  CE  MANUEL  OU  DANS  LES  SUPPLÉMENTS  
PUBLIÉS  PAR  SONY.

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

US and Canadian models:
CAUTION
The use of optical instruments with this 
product will increase eye hazard.

• Except US and Canadian models:

This label is located on the bottom of the
chassis.

The “HD Radio Ready” logo indicates that this 
product will control a Sony HD Radio

TM

 tuner 

(sold separately).
For HD Radio

TM

 tuner operation, please refer to 

the HD Radio

TM

 tuner Operating Instructions.

HD Radio

TM

 and the HD Radio Ready logo are 

proprietary trademarks of iBiquity Digital Corp.

The “SAT Radio Ready” 
logo indicates that this 
product will control a satellite 
radio tuner module (sold 

separately). Please see your nearest authorized 
Sony dealer for details on the satellite radio 
tuner module.
“SAT Radio,” “SAT Radio Ready,” the SAT 
Radio and SAT Radio Ready logos and all 
related marks are trademarks of Sirius XM 
Radio Inc. and XM Satellite Radio Inc.

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.

ZAPPIN is a trademark of Sony Corporation.

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

iPhone is a trademark of Apple Inc.

Windows Media and the 
Windows logo are trademarks 
or registered trademarks of 
Microsoft Corporation in the 

United States and/or other countries.

MPEG Layer-3 audio coding technology and 
patents licensed from Fraunhofer IIS and Thomson.

This product is protected by certain intellectual 
property rights of Microsoft Corporation. Use or 
distribution of such technology outside of this 
product is prohibited without a license from 
Microsoft or an authorized Microsoft subsidiary.

Content providers are using the digital rights 
management technology for Windows Media 
contained in this device (“WM-DRM”) to protect 
the integrity of their content (“Secure Content”) so 
that their intellectual property, including copyright, 
in such content is not misappropriated.
This device uses WM-DRM software to play 
Secure Content (“WM-DRM Software”). If the 
security of the WM-DRM Software in this device 
has been compromised, owners of Secure Content 
(“Secure Content Owners”) may request that 
Microsoft revoke the WM-DRM Software’s right 
to acquire new licenses to copy, display and/or 
play Secure Content. Revocation does not alter the 
WM-DRM Software’s ability to play unprotected 
content. A list of revoked WM-DRM Software is 
sent to your device whenever you download a 
license for Secure Content from the Internet or 
from a PC. Microsoft may, in conjunction with 
such license, also download revocation lists onto 
your device on behalf of Secure Content Owners.

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

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

7

3. DISASSEMBLY 

3-1. Disassembly 

Flow 

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

3-2. Cover 

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

3-3.  CD Mechanism Deck (MG-101Z-188//Q) .....................   14
3-4. ANTENNA 

Board 

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

3-5. MAIN 

Board 

...................................................................  15

3-6. SERVO 

Board 

.................................................................  15

3-7.  Chassis (T) Sub Assy ......................................................   16
3-8. Roller 

Arm 

Assy 

..............................................................  16

3-9. Chassis 

(OP) 

Assy 

...........................................................  17

3-10.  Chucking Arm Sub Assy .................................................   17
3-11. Sled Motor Assy 

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

3-12.  Optical Pick-up Section ..................................................   19
3-13. Optical Pick-up ...............................................................   19

4-1.  Block Diagram - AUDIO Section (1/2) - ........................   21
4-2.  Block Diagram - AUDIO Section (2/2) - ........................   22
4-3. Block 

Diagram 

 

- PANEL, POWER SUPPLY Section - ...........................   23

4-4.  Printed Wiring Boards - MAIN Section (1/2) - ..............   25
4-5.  Printed Wiring Boards - MAIN Section (2/2) - ..............   26
4-6.  Schematic Diagram - MAIN Section (1/4) - ...................   27
4-7.  Schematic Diagram - MAIN Section (2/4) - ...................   28
4-8.  Schematic Diagram - MAIN Section (3/4) - ...................   29
4-9.  Schematic Diagram - MAIN Section (4/4) - ...................   30
4-10.  Printed Wiring Boards - KEY Section - ..........................   31
4-11.  Schematic Diagram - KEY Section - ..............................   32

5-1. Main 

Section 

...................................................................  39

5-2.  Front Panel Section .........................................................   40
5-3.  CD Mechanism Deck Section (MG-101Z-188//Q) ........   41

  ..............................   42

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

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
Never look into the laser diode emission from right above when 
checking it for adjustment. It is feared that you will lose your sight.

If the optical pick-up block is defective, please replace the whole 
optical pick-up block.
Never turn the semi-fi xed resistor located at the side of optical 
pick-up block.

EXTENSION  CABLE  AND  SERVICE  POSITION
When repairing or servicing this set, connect the jig (extension 
cable) as shown below.

•  Connect the MAIN board (CN350) and the SERVO board 

(CN401) with the extension cable (Part No. J-2502-076-1).

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.

TEST  DISCS
Use following TEST DISC when this set confi rms the operation 
and checks it.

3-702-101-01 

YEDS-18 (for CD)

4-225-203-01 

PATD-012 (for CD)

NOTE  FOR  THE  20-PIN  CONNECTOR (CN901)
Do not use alcohol to clean the 20-pin connector (CN901) connect-
ing the front panel with the main body.
Do not touch the connector directly with your bare hand. Poor con-
tact may be caused.

Part No. 

                Description