Roberts ecologic 4 DAB radio?

I have a Roberts ecologic 4 DAB radio I turn it on the display lights up but can't get any channels in fact it won't do anything so I remove the back look at it and blow on it put it back together plug it in and it works any idea why this happens as I've done this a few times now . I have noticed the back of the speaker is opposite the transformer could it be a magnetic problem