I have a 42 inch Bush flat screen, problems with picture, shows picture and then cuts off, only sound remains?

Bush are one of the low cost-low quality range of televisions (including Alba, Baird, Celcus, Goodmans, Technicka, Tevion etc.). They are assembled by far eastern "box shifters" (there is no "Bush" factory any more since the 1960s) from the cheapest components and are built down to a low price rather than to a quality specification. This will not be a user-fixable fault. These days there is almost nothing that an unskilled person can do except to change the remote control batteries. It's probably a component failure in the remote control receiver in the set, or in one of the timebase circuits. If it's under guarantee then you must take it back to the shop. If the set is out of guarantee then it is unlikely to be economically repairable. A workshop will charge around £60 just to take the back off and diagnose the fault. You would still have to pay for the repair and components. On a low quality television if you fix one fault it is just as likely to develop another one shortly afterwards so you would never be absolutely certain about its reliability. I sincerely recommend that you bite the bullet and retire this television to a dignified end at your local recycling centre. Buy a decent brand made by the manufacture who's name is on the box. A Sony, Panasonic, Sharp or LG may cost a few ££ more but they're considerably better made and much more reliable. Buy from John Lewis and you'll get a price match to any local dealer and a free 5 year guarantee thrown in too.