Hello, I'm Shahid.Sorry to hear that you're having trouble with this but I'll do my best to help.
- Do you have Samsung TV remote and does it work?Thanks.
OK, have you checked the TV internal speakers are enabled to produce sound?
OK, what video input of TV is hooked to Virgin box?
Is it HDMI input or AV input?
OK, just to clarify, TV gives sound output when connect video source to AV input but no sound when connect video device into HDMI input of TV, is this correct?
OK, this TV has only two AV inputs, one is on side panel and one at rear.
It seems audio cable might be plugged in wrong jacks at rear of TV, can you confirm audio pins (red-white) plugged into correct jacks labeled as Audio L-R ?
OK, PS4 issue is separate and will discuss it later.
Since you connect yellow pin into side panel of TV then need to connect red-white audio pins into red-white jacks located below the yellow jack on side panel of TV to get sound when switch to AV input. Please reply back with the result and if problem resolved then a positive rating to answer would be highly appreciated.
Regarding TV switch Off when plug PS4, it seems failing capacitors on power supply board of TV issue which causing insufficient voltage supplies to other sections of TV and when TV gets high video resolution video signal via HDMI input, ti needs bit more current to process the signal and TV gets reset due to insufficient voltage supply because of failing capacitors. You would need to replace bad capacitors or entire power supply board to resolve this issue.
I agree, new TVs are cheap and repair costs more, this is an old model so it would be better decision to invest repair money on new replacement TV.