Bush digital LT22MICWA has lost digital signal?

I have purchased a Bush LT22MICWA Digital hd-ready TV recently and attached an indoor One for All digital aerial, which worked perfectly until the signal was lost two days ago! I have attached another aerial to it and it still doesn't work. I live in the shadow of Chrystal Palace, so have never had any difficulty getting a signal previously. I have gone through the manual and have come up with nothing. When I change the source nothing changes. Is there anything else that I can do?