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CX 300 Phone will not release audio control to the computer.

Occasional Visitor

CX 300 Phone will not release audio control to the computer.



I am lead technician for a university library, and we have just recently upgraded our phones in our building to CX300s and CX600s.  We have a recurring issue with the CX300 phone with several of our faculty.  The phone is tacking control of the audio on the computer and it will not relinquish it.  We tried using speakers, headphones of all platforms,  (USB, 3 1/4 jack, etc...), reinstalling the sound driver, looking at the settings in BIOS, but the sound always is comes from the phone.  There were instances where we could get headphones to work, and sometimes a sound bar / traditional desktop speakers, but there is one faculty member where everything that we have tried has failed.


All of these users are on Dell Optiplex 760s or higher, and we are using the onboard sound (front and back ports in some cases).  All of these computers are also running a Windows 7 Service Pack 1 build.  Any insight to this would be much appreciated.



Message 1 of 3
Polycom Employee & Community Manager

Re: CX 300 Phone will not release audio control to the computer.

Hello spclifto,

welcome to the Polycom Community.

Polycom, like another manufacturer, produce the CX300 as a reference design and our partner Microsoft provides all operating system drivers within their LYNC client.


I would suggest to post this question in a Microsoft endpoint forum or work with Microsoft Support on this issue.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.


Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 2 of 3
Occasional Visitor

Re: CX 300 Phone will not release audio control to the computer.



Thanks for the welcome!   :-)  I will definatly let you know what the Microsoft Community says.


Thanks Again!

Message 3 of 3