Just installed my new st2310 23" monitor on an xps 420 running vista, but I can't hear any sound through headphones plugged into the monitor. Any ideas how I get this to work please?
Your Manual shows an audio in/ audio out port for the optional sound bar instead of headphones. Connect your headphones to the front port on the computer itself. Monitors don't have sound. Even the HDMI port has only video. The sound card should be connected to the audio in port and the audio out goes to the soundbar.
That looks like they are labelled incorrectly. You would have to run a cable from the Audio Line-Out on your sound card into the monitor blue Audio Line-In. Then, test the headphones in the monitor green Audio Line-Out.
You can either use the method above me, or use a HDMI cable that also transfers HD sound from your PC, and Then plug in your earphones to the socket. It should work.