Can anyone help me with connections to a sony bravia tv please?

Try turning off tv speakers,or go into setup menu,and try sound offset if the tv headphones are in that part of setup,also turn surround off.site below for manual.Have you plugged it into the socket(pc sound in)next to pc video input or headphone socket below AV3.Maybe it has to do with the jack plug not being correct,OK for speaker output on pc but not for headphone output.Try a pair of headphones in the tv.