Lg 47LB9DF lcd Tv turning itself off whilst... I recently purchased this lcd tv only 1 month ago.

Question

I recently purchased this lcd tv only 1 month ago. I brought the unithome and apon channel surfing on the hd channels within 2 seconds thelcd screen goes dead makes an audible click through the speakers andstarts up again with the operation led flashing just like whenswitching the unit on. Now i thought it was a faulty unit but had asecond unit delivered and it does the exact same thing. i.ve had mymains and antenna checked. i took it back to get a refund but in thestore the unit wouldn't fault! they sent me back home still suggestingsomething was wrong at home which is 1 hour away. i've just come homefrom trying the tv at 5 other mates houses and it done the channelsurfing black out thing at all my mates. its driving me mad!!!!!