My Commando SP-8320 no longer flashes both Red & Blue like it should in order to pair with another device. I can't even pair it with the I-Phone I've used it with over the last couple years.

SOURCE: headset does not flash red/blue so I can pair it with my phone

To get it into pairing mode (flashing red and blue) turn the headset off.  Hold the main button down until the light goes red and then off.  Then push and hold that same button and keep holding it even after the blue light comes on.  It will now go into pairing mode, flashing red and blue.  Set your cell phone to find it and it should work.

SOURCE: 925 Plantronics will not pair with cell phone.

You are holding down the main button too long.  When it flashes blue and red it is now in pairing mode.  To turn on the headset hold down the main button until you see the blue light come on, then let go.  If you hold it any longer this is when it goes into pairing mode.

SOURCE: old phone quit and blue tooth won't pair with new phone

Hold the volume buttons on the side while holding the call button for 10 seconds. It will reset the bluetooth and remove any other devices it may have been paired to. Then turn it off, back on and it will eventually stay lit blue and then you need to set it up through your phone. I hope this helps, I had the same problem and mine is working fine!

SOURCE: I have an Explorer 210 series. It will no longer pair

Just this morning I was able to pair this headset with my phone. Before, it was paired to my PS3. The key is to hold down the big round button on the outside until the light flashes red/blue (this is quick-pair mode) then just have your cellphone search for bluetooth devices and you're done!

Testimonial: "I tried that but I bet I didn't do it long enough. Thank you so much (I exchanged it already but will keep in mind). Thank you again!"

SOURCE: Head set not pairing with sony erricson k750i

The solution for paring the explorer 240 is found in the bottom of the product page for the embedded link on the User Guide Link. I have also provided the instructions below. I hope this helps

How to Pair Your Phone With Your Headset for the First Time

1 Turn on the Bluetooth feature on your phone.
For most phones, select Settings/Tools > Connections >
Bluetooth > On. See your phone’s user guide for more information.
2 Turn the headset on.
Turn on your headset by sliding the Power Switch toward the microphone. Wait until the indicator light flashes red then blue.
If you don’t see the red then blue flashes, turn the headset off, then turn it on again. Press and hold the Call Control button until you see the red then blue flashes that indicate pairing mode status.
3 Set your Bluetooth phone to ‘discover’ to locate the headset.
This usually involves going to ‘setup’, ‘connect’ or ‘Bluetooth’ menu on your phone and selecting the option to ‘discover’ or ‘add a device’.
4 Once available headsets are listed, select your headset (for example 2XXPlantronics or 3XXPlantronics). If prompted for a passkey, enter 0000.
When pairing is successful, the indicator on your headset flashes blue. Your phone will also confirm when pairing is complete.

John M