A couple of things, alright maybe three, you can try that may sound inconceivable but people do forget to check. First, make sure cords are in their right slots. Second, locate the best compatibility setting (slide located on port side of amplifier) and third, lift up the handset on the phone (it's okay, you're not alone if you forgot this step). If you're still having problems and it's less than a year old, contact Plantronics at 800-544-4660 x5 x5538 for warranty replacement.

Good luck from Headsets Direct!