MEX-BT2500 - Sony Car Audio Service Manual (repair manual). Page 5

5

KEY board

front panel

AUX jack

When repairing, the complete BT board (A-1243-387-A) should be
replaced since any parts in the BT board cannot be repaired.

When repairing, the complete SERVO board (A-1177-201-A) should
be replaced since any parts in the SERVO board cannot be repaired.

To replace the AUX jack requires alignment.
1. Insert the AUX jack into the front panel.
2. Place the KEY board on the front panel and align the terminals

of the AUX jack with the holes in the KEY board.

3. Solder the three terminals of the jack.

• Set to be tested (MEX-BT2500)

• Cellular phone (Recommended SEMC K320i or K800i, or

select from connectable cellular phones list)

• Speaker connection (at least Front L/R ch)

• DC power supply (12V)

Turn on the Bluetooth function of the cellular phone in advance.
Remove a Bluetooth device connected to the cellular phone in
advance. (at least, remove XPLOD)

• No other Bluetooth device is making a communication in the

periphery. (within 20m)

• No other MEX-BT2500 is supplied with electric power.

• There are no two or more wireless LAN access points in the

periphery. (with 50m) (one is OK)

• The set should be tested in a place such as a meeting room,

free from ambient noise.

• The speaker at the far end should be in a place such as another

meeting room separated acoustically.

Install the MEX-BT2500 on the desktop.

• There is no fault if a talking can be made by adjusting

appropriately the volume of the telephone of the other party
and the cellular phone connected through the Bluetooth,
besides the setup of MEX-BT2500.

• The speaker’s voice will become loud naturally if the periphery

is noisy, or become low if quiet. (even though the speaker
intents to talk on the same volume level)

• The speaker’s voice will become loud naturally if the other

party’s voice is loud.

1. Press the [BLUETOOTH] button for 7 seconds to check if the

BT logo changes from lighting to blinking.

2. Search peripheral equipment from the cellular phone to check

if “XPLOD” is found.

3. Search peripheral equipment from the cellular phone apart from

the set about 5m to check if “XPLOD” is found.

4. Check if peripheral equipment can be registered to the cellular

phone (pass code 0000).

5. Make a connection to the cellular phone to check if the HF

logo lights up. (This may be conducted at the same time in
item 4)

6. After making a connection to the cellular phone, move the

cellular phone apart from the set about 5m to check if the
connection is held.

7. After switching the source of the MEX-BT2500 to other than

BT PHONE (i.e. TUNER) to check that a sound is generated,
make a call to the cellular phone connected to the set.

8. Check that the sound being played is interrupted and in turn

the ring tone is heard. (the built-in sound of the set will be
generated or the ring tone of cellular phone will be heard
depending on the cellular phone)

9. Press the [PUSH SELECT] button for a short time to check that

the conversation can be made.

Under normal conditions, the battery will last 
approximately 1 year. (The service life may be 
shorter, depending on the conditions of use.)
When the battery becomes weak, the range of the 
card remote commander becomes shorter. 
Replace the battery with a new CR2025 lithium 
battery. Use of any other battery may present a 
risk of fire or explosion.

Notes on the lithium battery
•

Keep the lithium battery out of the reach of children. 
Should the battery be swallowed, immediately 
consult a doctor.

•

Wipe the battery with a dry cloth to assure a good 
contact.

•

Be sure to observe the correct polarity when 
installing the battery.

•

Do not hold the battery with metallic tweezers, 
otherwise a short-circuit may occur.

1

2

c

Battery may explode if mistreated.
Do not recharge, disassemble, or dispose of
in fire.