Sony MEXBT3900U Car Stereo Manual

The Sony MEXBT3900U is a single-DIN car stereo with built-in Bluetooth for hands-free calling and audio streaming, USB port for iPod/iPhone and USB storage, CD playback with MP3/WMA/AAC support, AM/FM tuner with 18 presets, front auxiliary input, 52W x 4 high power output, detachable faceplate security, and customizable illumination. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Devices 7. Playing Media 8. Bluetooth Functions 9. Care & Maintenance 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Main unit with detachable faceplate, Remote Control (optional), Wiring harness, Antenna connector, USB port, AUX input, Microphone input for Bluetooth.

FeatureDescription
BluetoothHands-free calling and audio streaming from compatible devices
USB portFor iPod/iPhone direct control and USB flash drive playback
CD playerPlays CD, CD-R, CD-RW (MP3/WMA/AAC)
AM/FM tuner18 station presets (12 FM, 6 AM)
AUX input3.5mm front panel auxiliary input for external audio
Power output52W x 4 channels (max)
Detachable faceplateSecurity feature to prevent theft
Customizable illuminationAdjust display color to match vehicle interior
Remote control readyCompatible with optional Sony remote
EQ settingsBuilt-in equalizer with preset sound profiles

Installation

Unpack and inspect contents. Ensure vehicle battery is disconnected before installation.

  1. Remove existing stereo: Use proper removal tools for your vehicle.
  2. Connect wiring harness: Match wire colors (red-ignition, yellow-battery, black-ground).
  3. Connect antenna: Plug antenna cable into rear of unit.
  4. Mount unit: Secure in dashboard using supplied sleeve and brackets.
  5. Reconnect battery and test functions.

WARNING! Disconnect vehicle battery before installation to prevent electrical shorts. Professional installation recommended.

First-Time Setup

Power on unit; follow initial setup prompts.

  1. Set clock: Press SOURCE to turn on, enter clock setting mode.
  2. Program radio stations: Tune to desired station, press and hold preset button.
  3. Pair Bluetooth: Enable Bluetooth on phone, select "MEXBT3900U" from device list.
  4. Adjust sound settings: Use EQ menu to select preset (ROCK, POP, etc.) or customize.
  5. Set illumination: Choose color from options in display settings.

CAUTION! Do not operate while driving. Park vehicle safely before adjusting settings.

Specifications

Controls and Settings

Front Panel: POWER/VOLUME knob, SOURCE, BAND, AUX, USB, CD eject, Menu buttons.

Remote (optional): POWER, VOLUME, SOURCE, TRACK UP/DOWN, PRESET, MUTE.

Audio Settings: EQ (FLAT, POWER, VOCAL, CUSTOM), Bass/Treble, Loudness, Fader/Balance. Radio: Manual/seek tuning, preset memory. Bluetooth: Pairing, phonebook access, call history. Display: Clock setting, illumination color (Red/Blue/Green/White), Dimmer. Security: Detachable faceplate removal.

Connecting Devices

USB: Connect iPod/iPhone or USB drive. AUX: 3.5mm cable from external device. Bluetooth: Pair mobile phone.

  1. Turn off vehicle before connecting devices.
  2. For USB: Use certified cable; device may charge while connected.
  3. For AUX: Plug into front panel jack, select AUX source.
  4. For Bluetooth: Enable pairing mode from source menu.

Tip: Use high-quality USB cables for reliable connection and charging.

Playing Media

Supports CD, USB, AUX, Bluetooth audio.

  1. Insert CD: Press eject to open tray, place disc label up.
  2. USB playback: Connect device, select USB source, navigate folders with rotary knob.
  3. AUX playback: Connect cable, select AUX source, control volume on source device.
  4. Track control: Use SKIP buttons or rotary knob to navigate.
  5. Repeat/shuffle: Press RPT or RDM during playback.
  6. Fast forward/rewind: Press and hold SKIP buttons.
  7. Folder navigation (USB): Turn rotary knob to browse.
  8. CD text/ID3 tag display: Supported when available on disc/USB.

WARNING! Do not insert damaged discs. Avoid USB drives with multiple partitions.

Bluetooth Functions

Hands-free calling: Answer/end calls with front panel button. Audio streaming: Play music from Bluetooth devices. Phonebook access: Download contacts to unit (supports up to 1000 entries).

  1. Pairing: Enter Bluetooth menu, select "Pairing," search from phone.
  2. Auto reconnect: Once paired, reconnects when in range.
  3. Voice dial: Press and hold call button to activate phone voice commands.
  4. Call history: Access recent calls from unit menu.

Care & Maintenance

Clean with dry, soft cloth. Remove faceplate before cleaning. Do not use solvents or abrasives.

CAUTION! Do not spray cleaners directly on unit. Keep liquids away from buttons and ports.

Regulatory Information

FCC ID: AK8MEXBT3900U. Complies with Part 15 of FCC rules. This device complies with Industry Canada license-exempt RSS standard(s). Bluetooth is a trademark of Bluetooth SIG, Inc. Sony and the Sony logo are trademarks of Sony Corporation. For support, visit www.sony.com/electronics/support or contact 1-800-222-7669.

Troubleshooting

SymptomPossible CauseCorrective Action
No powerWiring/ fuseCheck connections; verify ignition wire has 12V; check vehicle fuse.
Bluetooth not pairingDistance/ settingsEnsure device within 3 ft; delete old pairing from both devices; retry.
USB not recognizedFormat/ powerUse FAT32 format; try different USB port/cable; device may need external power.
Poor radio receptionAntenna connectionEnsure antenna plugged in fully; check antenna condition.
CD skips or ejectsDisc/ vibrationClean disc; ensure proper mounting to reduce vibration; use quality discs.
No sound from speakersWiring/ settingsCheck speaker wires; verify fader/balance not set to extreme; test each channel.

Reset: Press reset button on faceplate with paperclip.

Service: 1-800-222-7669; www.sony.com/electronics/support

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