Use TV as Speakers for PC (using RCA to 3.5mm)

[Deleted member 2158095]

I recently got a flat screen TV working as a second monitor for my PC, and set it up with a VGA cable.
I've now bought a RCA to 3.5mm cable but I can't set it up.
I am connecting the RCA in the audio jacks on my TV and the other end on my back panel sound jack. The TV is detected but no audio is played through it. When I test the device the sound settings show those audio green audio bars indicating sound is being played, but it's not working.
Am I doing something wrong?
Thanks in advance for your help.

 

[americanaudiophile]

Check the owners manual of the TV. You may have to assign the audio to the VGA input.

 

[Deleted member 2158095]

Check the owners manual of the TV. You may have to assign the audio to the VGA input.

I was given this television by my parents and I don't have any information about it other that it's a samsung LCD and it's roughly 7 years old. TV settings suggest only PC, Ext. and TV are the only available options, with AV being unused.
Got any other suggestions?

 

[Alabalcho]

It is quite possible that RCA audio in is used only when "yellow" RCA (or component) video input is used. Find your TV' manual, and see whether there's a way to assign audio inputs with VGA input.

 

[Deleted member 2158095]

It is quite possible that RCA audio in is used only when "yellow" RCA (or component) video input is used. Find your TV' manual, and see whether there's a way to assign audio inputs with VGA input.

After finding out the model and looking up the online manual I found I need a 3.5mm to 3.5mm for VGA use. Thank you everyone for your help.