DOWNLOAD Sony MEX-BT3900U / MEX-BT3950U / MEX-BT39UW Service Manual ↓ Size: 3.06 MB | Pages: 48 in PDF or view online for FREE

6 two coil springs (damper) (natural)

7 coil spring (damper) (green)

8 chassis (OP) assy

5

1 tension spring (KF)

2 gear (LE1)

3 lever (D)

4 slider (R)

3 chucking arm sub assy

2

1 spring

Note 1: Have this portion receive the chassis.

Note 1: Have this portion receive the chassis.

Note 2: Be careful not to touch the turn table.

3 sled motor assy

1 spring

2 three serration screws

u 3)

u 3)

Note 1: Place the stand with care not to touch the turn table.

Note 2: Never remove these parts since they were adjusted.

Note 3: Take care to prevent the chassis from being bent
 

when tightening the three machine screws.

MEX-BT39UW/BT3900U/BT3950U

Setting method:
1.  Press the [SOURCE/OFF] button for 1 second to turn the pow-

er off.

2.  Press the [4] 

→ [5] → [1] buttons sequentially (the [1] button 

is pressed for two seconds).

3.  It is set to the test mode, and all segments of the liquid crystal 

display light.

Releasing method:
Press the [SOURCE/OFF] button for 1 second.

MICROPHONE  AUDIO  LOOPBACK
To confi rm the state of the external microphone/internal micro-
phone used when a handsfree function is used, the microphone 
audio is output from the speaker.
The breakdown judgment of the microphone can be done without 
connecting H/F with the cellular phone.

Procedure:
1.  Enter the test mode.
2.  Press the [SOURCE/OFF] button to select the Bluetooth Phone 

function.

3.  On/off of the microphone audio loopback function changes 

whenever the [2] button is pressed (“ALBM” is displayed in 
the liquid crystal display).

 

ON

Lit

OFF

None

THE  EXTERNAL  MICROPHONE  DETECTION  
STATE  DISPLAY
Connected confi rmation of the external microphone detection line 
is done.
The trouble that doesn't change into an external microphone occurs 
when this detection circuit is broken.

Procedure:
1.  Enter the test mode.
2.  Press the [SOURCE/OFF] button to select the Bluetooth Phone 

function.

3.  Plug in the external microphone into the MIC IN terminal.
4.  The detection state of the external microphone is displayed in 

the liquid crystal display (“TRACK” is displayed).

 

In this state, when the external microphone is pulled out, the 
beep sound is output.

1

2 optical pick-up section

Note: Be careful not to touch the lens and hologram
 

terminal when removing the optical pick-up section.

There is space at the end of the 
leaf spring (sub guide) to avoid 
contact with the slide.

1 pan tapping screw

u 2.5)

2 leaf spring (sub guide)

3 leaf spring (OP)

5 optical pick-up

4 lead screw assy

Prevent the end of the 
leaf spring (sub guide) from being 
in contact with the OP slide base.

Prevent the end of the 
leaf spring (sub guide) from being 
in contact with the OP slide base.

MEX-BT39UW/BT3900U/BT3950U

xSIGNAL PATH

: USB

: CD PLAY

: AUDIO

: Bluetooth

: MIC

xR-ch is omitted due to same as L-ch.

D731

2

3

1

OPTICAL PICK-UP

BLOCK

(DAX-25A)

CD MECHANISM DECK

(MG-101P-188//Q)

SWITCH

BOARD

SERVO BOARD

BT BOARD

(PATTERN ANTENNA)

MIC201

AU_FL_CH

RXD

CD_ON

CDM_ON

VBUS_ON

24 MC_TX
37 CD_ON
38 CDM_ON
51 VBUS_ON

TXD

USB_D-

USB_D+

D-

VBUS

VBUS

D+

22 MC_RX

XSYS_RST

SP_CLK

49 SA_CLKOUT

SP_DATA

48 SA_DATAIN

SYS_RST

BU_CHECK

BU_CHECK

A_ATT

AU_FR_CH

R-CH

LCH_P

RCH_P

R-CH

LCH_N

RCH_N

R-CH

Z_MUTE

EJECT_OK

WAKE_UP

40 Z_MUTE

BU+3.3V

39 WAKE_UP

VDD_3.3V

SERVO+3.3V

BU_3.3V

BU+3.3V

DR_6V

MECHA+6V

88 BT_MIC_DET

D204

D404

D403

D401

BATT

AT

T

58

SYSTEM CONTROLLER

IC501 (1/3)

MIC
+3.3V

MIC B+

MIC+_IN

MIC_OUT

B+ SWITCH

Q201, 202

MIC INPUT

SELECT

IC201

MODULE_PON

UART_RTS

RESET

BT_POWER

87

BT_CTS

85

UART_CTS

BT_RTS

84

BT_RESET

86

UART_TX

UART_RX

BT_RX

78

MUTE

BT_MUTE

67

BT_TX

77

BT-L_P

BT-L_N

ATT

FL_CH

AU_RL_CH

AU_RR_CH

R-CH

RL_CH

AU_SUB_CH

SUB_CH

AU_IN_LCH

AU_IN_RCH

R-CH

IN_LCH

A

MUTE

DRIVE

Q407, 409

B

CN902

BU +3.3V

RESET SIGNAL

GENERATOR

IC403

S401

RESET

RESET

12

MIC IN

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