Hi @deelo ,
If you have Win 10 installed, right click on the Windows Start button (left side of Taskbar). An options window opens and a link to Device Manager is there.
Also if the audio is OK in the laptop's speakers, then go to ''Control Panel > Sound > Playback'' and check that the headphones are shown as an option when they are plugged in.
To get to Control Panel, type ''Control Panel'' in the Windows search box (left side of Taskbar) and select the Control Panel app that appears