No Audio Detected on my LG RD590

Hello,
The sound does not work. I get a message that ,no speaker or headphones are connected.
When I open the device manager, the sound devices are enabled and installed.
I tried to solve the problem using the "Solving Problems with Windows"
Message is displayed that the device is disconnected. Moreover, in the task bar on the left,
There is an X on the icon of the speaker.
My pc is LG RD590.
Thanks.
