Hi, I have bought Plantronics Explorer 320 Headset today, and after charing 2 hrs, I have tried all the by pressing 1 sec, 2 sec, 3 sec,.....it does not getting power on the headset....but while charging its emitting the blue indigator sometimes red indigator also.. Please help me how to make this use of... Thanks MCK

SOURCE: plantronics 320

i am having the same problem with my w850i and this plantronics explorer 320 - i wonder if it is a fault with the sony ericson phone ?

SOURCE: bluetooth wireless

It's real easy, the PIN code is 0000. That's right it's just four zero's, the PIN is the same regardless of brand or model of headset. So if you need the pin, here it is, and I hope this helps.

http://www.pchelpforanyone.blogspot.com/

SOURCE: headset setup

Begin with headset turned off.
1. Press call control button for
6 seconds. Release button when
indicator light flashes blue and
red. Headset is ready to pair with
Bluetooth device.
NOTE The headset can pair to
multiple Bluetooth devices, but
will only connect to one device
at a time. The headset will automatically
connect to the last
device to which it was connected.
2. While the headset is flashing red
and blue, use the phone menu
to search for Bluetooth devices
and select “3XXPlantronics”.
3. When prompted for passkey enter
0000. Headset will flash blue when
paired successfully.

SOURCE: Plantronics Explorer 220 headset needs reset to new phone

Start with the device off but fully charged. Press and hold the call control button for 8 seconds; at this point, you'll see the light flash blue then red. You'll have two minutes to connect it to your new phone. Use the passkey 0000 after your phone finds the headset.

SOURCE: miss place passcode for plantronic 320 Headset

try the passcode 0000. That's 4 zeros.