cw 4000. my channels are gone. i see a strong sig/quality on the channel, but its blank. used to be i could go to say, channel 111, let it come in then go back to another, and it would come in. now, nothing. any help? tried reinstalling bin, new bin etc... no help. second question, when i hit scan all, the unit scans all the transponders on 110 then 119, but some of the transponders have no signal or quality, while others have 100%. is that normal?