Thanks for the responses.
The item is a TV, and I bought it off ebay (I know, probably a bit stupid). Basically it works for a while but then the power cuts, the screen goes black and the buttons stop responding. If I unplug it at the mains and plug it back in it starts working again, or if you wait long enough (about 5 minutes) then it comes back on.
The item was only bought a month ago. I guess the good thing about it being sold on ebay means I can show you the details:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewIte m&rd=1&item=110169522902&ssPageName=STRK:MEWN: IT&ih=001
As you can see it was sold as in complete working order, acording to the description.
Whenever I've had this sort of problem before with goods bought off ebay I've always contacted the seller and they've been happy to replace or refund the item, however when I contacted this seller he said that he hadn't come across that problem before, and suggested I contact Acoustic Solutions about it (who said that since Argos are the only people who sell it I should contact the Argos support line).
What do you think?
Andrew