Sharp TV only a yr old and losing sound.

wingobins

(I posted this in around the home Forum but thought I might be best posting here). I need some advice please.

My parents bought a Sharp digital tv from Argos last yr around oct/nov time but the sound on the tv has been going off every 5-10 mins which has been happening for about 3 months now. The receipt and guarantee has been mis-placed (possibly thrown away) by accident and after getting in contact with Argos and sharp are told there's nothing they can do. They're at their wits end and as pensioners can't afford to replace it either. My dad has even looked up about the same model and read reports of it being faulty!
Is there anything they can do to get the tv replaced or fixed?
I've always thought of sharp as a good make and would expect it to last beyond a year!
It's never happened before with any other tv they've had and dad thought it might be when they have heating on and even turned it right down but it's still happening.

Any help would be appreciated.

closed

is the freeview signal ok, and/or scart/hdmi connector secure if using a set top box

loses sound on all channels?

do the headphone/phono ouputs work when sound goes off

tried a retune?

tried a factory default reset?

how did they pay, cash or credit card, or debit card?

if they have a hifi, they could plug in a freeview receiver/stb into that

wingobins

They don't have a hifi and they re-tuned it when the area upgrade happened in sept. I suggested they unplug all leads and plug in again and they've tried that. I've been there when it's gone off several times and it is quite annoying. They paid cash for it. They have a TiVo box and even disconnected that but still the problem exists.