Sony MEX-BT4750U Operating Instructions Manual page 29

Radio reception
The stations cannot be received.
The sound is hampered by noises.
The connection is not correct.
t Connect a power antenna (aerial) control lead
(blue) or accessory power supply lead (red) to the
power supply lead of a car's antenna (aerial)
booster (only when your car has built-in FM/AM
antenna (aerial) in the rear/side glass).
t Check the connection of the car antenna (aerial).
t If the auto antenna (aerial) will not go up, check
the connection of the power antenna (aerial)
control lead.
Preset tuning is not possible.
• Store the correct frequency in the memory.
• The broadcast signal is too weak.
Automatic tuning is not possible.
• Setting of the local seek mode is not correct.
t Tuning stops too frequently:
Set "LOCAL-ON" (page 21).
t Tuning does not stop at a station:
Set "LOCAL-OFF" (page 21).
• The broadcast signal is too weak.
t Perform manual tuning.
During FM reception, the "ST" indication
flashes.
• Tune in the frequency accurately.
• The broadcast signal is too weak.
t Set "MONO-ON" (page 21).
An FM program broadcast in stereo is heard in
monaural.
The unit is in monaural reception mode.
t Set "MONO-OFF" (page 21).
USB playback
You cannot play back items via a USB hub.
This unit cannot recognize USB devices via a USB
hub.
Cannot play back items.
A USB device does not work.
t Reconnect it.
The USB device takes longer to play back.
The USB device contains files with a complicated tree
structure.
A beep sounds.
During playback, the USB device has been
disconnected.
t Before disconnecting a USB device, make sure to
stop playback first for data protection.
The sound is intermittent.
The sound may be intermittent at a high-bit-rate of
more than 320 kbps.
Bluetooth function
The connecting device cannot detect this unit.
• Before the pairing is made, set this unit to pairing
standby mode.
• While connected to a Bluetooth device, this unit
cannot be detected from another device. Disconnect
the current connection and search for this unit from
another device.
• When the device pairing is made, set the Bluetooth
signal output to on (page 18).
Connection is not possible.
• Connect to this unit from a Bluetooth device or vice
versa. The connection is controlled from one side
(this unit or Bluetooth device), but not both.
• Check the pairing and connection procedures in the
manual of the other device, etc., and perform the
operation again.
The talker's voice volume is low.
Adjust the volume level.
A call partner says that the volume is too low
or high.
Adjust the volume accordingly using Mic Gain
adjustment (page 18).
Echo or noise occurs in phone call
conversations.
• Lower the volume.
• If the ambient noise other than the phone call sound
is loud, try reducing this noise.
E.g.: If a window is open and road noise, etc., is loud,
shut the window. If the air conditioner is loud, lower
the air conditioner.
The phone is not connected.
When the Bluetooth audio is played back, the phone is
not connected even if you press
t Connect from the phone.
The phone sound quality is poor.
Phone sound quality depends on reception conditions
of cellular phone.
t Move your car to a place where you can enhance
the cellular phone's signal if the reception is poor.
The volume of the connected audio device is
low (high).
Volume level will differ depending on the audio
device.
t Adjust the volume of the connected audio device or
this unit.
continue to next page t
(handsfree).
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