Here is a link to configure the TV LINK (which I am assuming is the same as Magic Eye, please correct me if I'm wrong) click here Also, try scanning for the box at a different frequency as you may be picking up a 'ghost' channel.
If you have switched the RF out power supply on and have acidentily touched the end of the coaxial cable or the TV Link trying to plug it into the TV this can cause a problem. Unplug the Digi box for a few minutes and plug back in.
If you have connected it to a video recorder you may find the RF frequency is conflicting with the Digi box.
Do you have the aerial plugged into the Sky+ box as well? In some cases this causes interference between the RF output from the Sky box and the analogue TV channels. Unplug the aerial and try it and if the signal improves, then you'll need to move the Sky+ box to another frequency out of the way of the analogue channels. To do this, press Services, then 4, 0, 1 then Select. In the installer menu, press 4 for RF Outlets and change it to a channel number away from the analogue TV channels. You'll need to keep tuning the TV to the new number as well so that it stays tuned to the Sky box. You might need to try a few different channel numbers, but eventually you'll find one that works. If the picture is still snowy after you unplugged the aerial, then the problem could be with the cable connectors so try another cable.