Try installing a signal booster, the yellow brick konig ones of fleebay are supposed to good, the cheapo argos slx 1p ones do the job as well though with variable gain
another quick thing to look at is the cable make sure all connections are good, and make sure there are no bends in the cable if you hold the cable then slowly bend it you will see what i mean you get higher ber and the chanel will go off
I got a 500c last week said had phillips tuner in it for best results but had a poor ber rate a swell snr in low 80's used the yellow brick helped on 90% of all channels argos thing never worked for me. Go to Discovery channels they have the weakest snr if u get them you'll get everything!
