I'm assuming its the failing of digital systems compared to analogue. But for the record cheapest and nasty Durabrand PSTB 1 freeview box for multiplexed digital transmitted on UHF. There is some normal loss of signal problems on a few channels leading to partial loss of picture and/or sound or even total loss of content due to ,presumably, inadequate aerial, (occurs when the sun is in line with the aerial but behind the Yaggi reflector end ). But real query concerns on odd occassions for very strong digital channels where there is never any partial loss there is sometimes cutting from normal sound and vision to total loss, immediately, without any partial loss state, maybe due to a few cycles of mains voltage dropping out. Only occurs perhaps once a month so no problem really The channel will stay off unless you reset by changing up and back down a channel or switching off and back on. But last week recording to VCR this happpened so no human intervention to reset so 3/4 hour of perfect black video and silence until, via the internal timer settings, it was changed to another channel and reset to that channel and stayed perfectly with it to the end of that programme. Not a transmission fault. Is this intractable ? , ie the failing of digital systems over analogue where some information gets through however degraded on sound or vision but with digital, in this version anyway, it cannot recover of its own accord , or just a bug with this brand ?.
-- Diverse Devices, Southampton, England electronic hints and repair briefs