Hi, I have a Sony Bravia KDL40BX400. I have tried connecting my PC speakers to it but I only get sound from one speaker, (completely missing the sub woofer and remaining speaker). Do I need Sony TV speakers or is it a socket/connector problem on my behalf? Thank you for any assistance.

You should be getting sound out of both speakers, and maybe the subwoofer depending on the design of the speakers. You do not need Sony speakers.

First how do the speakers connect to the TV? Headphone? RCA (white/red)? Fiber optic?

Next, check that the connection is secure. If so, try connecting the speakers directly to another device. If you have the same result as when they are connected through the TV, then try swapping the connection if you are using the RCA cables and see if there is now no sound at all or if the sound moves from one speaker to another.

Post back with your results.