To deal with the problem you must clear the channel list completely and then rescan - if your box has it in the menus, please the 'installation menu' to do an initial scan or a reset to factory settings or First Time Installation. You MUST delete the entire existing list of channels. On most boxes this technique can be also be used:
2) unplug the aerial from the Freeview box by disconnecting the cable from the 'RF in' socket;
3) wait 30 seconds;
4) plug Freeview box (or idTV) mains back in;
5) do a complete scan for channels - it will fail without the aerial. (This may be in the installation or initialization menu, and is distinct from any 'add channels option'). Once this is done your channel line up should be empty;
6) reinsert aerial by reconnecting to the 'RF in' connection;
7) do a complete scan for channels again.
The Freeview channel line-up provided by six "multiplexes" - each of which carry five or more TV channels, radio channels, text services and EPG data. In this diagram each ROW represents a multiplex. If you are still missing a whole multiplex (ie everything on the row) you may need to replace your aerial with a wideband type, purchase a larger aerial or you may have interference from a VCR, games console, Sky Digibox or similar.
Losing signal on BBC Northwest. Tends to be intermittent but at times is completely unwatchable. Problem started around 10 October 2016. Re-tune to BBC West Midlands and signal is perfect but then we lose our local news. Postcode LL12 8YG. Any suggestions, please.
Hugh Sharp: Your just 28km from Moel-Y-parc witha clear sight line, so something is wrong. Check signal strength, could be too high, in which case look for 'too much of a good thing' on this site, and if its very low (assuming your on the correct transmitter), then something is up with the aerial.
tracy darlington: If, as appearances could suggest you are connected into a communal aerial system? then check if anyone else in the block is also being affected by the problem, and if they are, then the matter should be referred to either the landlord or the building maintenance department, as they are responsible for the maintenance / repair of the system.
If though on the other hand they are not, then check the jumper lead connecting your TV into the wall socket etc.
2 days ago several TV channels had the error "No signal'. The most obvious missing channel was ITVWales. The signal quality and strength meters were at zero for this channel.
I live in a bungalow, the aerial is in the attic and I have all new wiring. As I'm technically qualified I checked the wiring throughout the system and even simplied the wiring by bypassing the amplifier/splitter etc. It occured to me that maybe the channels are not being transmitted by the Pontypooltransmitter so i check on line but there are no publicised works being undertaken. I tried moving the aerial (It had not moved in my opinion) which is also new and up to this point as provided faultless reception. No signal possible on missing channel no matter where I moved it.
Late last night I Turned TV off unplug tv lead, turned tv back on and rescanned channels. No channels of course.
Then reconnected everything as before and retuned TV, only 77 channels found.
Some channels still missing.
This morning even though I had changed nothing, not even removing tv lead I retuned the TV and 88 channels were found, Signal strength and signal quality for ITV were now visible and similar/greater values than BBC.
I suspect either the transmitter wasn't transmitting or weather conditions have played a part in this remarkable change even though the weather is basically unchanged.
I don't know if my neighbours had similar issue.
A most annoying problem as i was contemplating installing an outside aerial as the next step.
It is probable that your reception is being affected by a temperature inversion atmospheric condition that has been around for a few days. By retuning you will have lost all the channels you originally had. All you can do now is to retune each day to see when they all come back.
BTW, it is usual to give a full post code so that we can determine the exact reception coinditions for your locality.