Hi all,
I've got an 1100S that has been working well since I bought it (second hand) a few months ago, although recently I've been seeing occasional picture breakup which has started getting worse. I've been keeping an eye on the signal strength/quality to troubleshoot and most of the time the strength is showing 80%+ and quality flitting between 90-100% however every so often BOTH tuners drop to 0 and NO SIGNAL for a second, then straight back to how they were before. I did originally suspect that this may be due to tree foliage blocking the signal (as it is quite windy today) however the trees in my garden don't seem to be in the line of sight of the dish - also I'd expect the signal strength to drop in a more linear way rather than going from full strength to zero instantly.
The dish looks like quite an old original Sky Digital dish with a Sky branded MK4L LNB so I did suspect that maybe the LNB is failing? Given I'm losing both tuners at the same time it can't be a cabling fault so I guess it's either the LNB or the box's tuner (although again would that affect both at once?). I'll wait to see if the situation improves when the wind drops, but if not I guess an LNB swap would be the next obvious step?
Good to hear your thoughts 
