The picture freezes for a second, breaks into blocks, or you simply get no signal halfway through a film. When TDT fails, the television is almost never at fault — what fails is the signal reaching it.
That is good news, because signal can be measured and fixed. Here is how to narrow the problem down yourself — whether it is your set, your outlet, the aerial or the building's installation — before anyone climbs onto a roof.
Why TDT fails suddenly rather than gradually
Analogue television degraded gracefully: you lost quality, got some snow, but still saw something. Digital does not behave that way. Either enough signal arrives and the picture is perfect, or it arrives marginal and you get pixelation, audio dropouts and channels that disappear.
Which is why an installation that "was fine yesterday" can fail overnight: it had been running at the edge for a long time and some small extra loss pushed it below the threshold. A slightly corroded connector or a heavy downpour is enough.
Step 1: does it fail on every TV, or just one?
This question halves the problem and saves half the work.
Only one television or one room: the aerial and amplifier are fine, because everything else works. The fault is on that particular leg — the cable to that outlet, a splitter, or the wall socket. Also rule out the flylead between the socket and the TV, which is the cheapest thing to check.
Every television in the property: the problem sits before the distribution — the aerial, the amplifier, or the downlead.
Step 2: retune before anything else
If channels have vanished suddenly but the remaining ones look perfect, try retuning from the television's menu. Broadcast frequencies change occasionally and sets do not always notice on their own.
It is free, takes a couple of minutes, and resolves a decent share of call-outs. If channels are still missing or pixelating afterwards, you know the problem is signal.
Step 3: if the whole property is affected, look up
The aerial
Wind knocks it out of alignment or loosens the mast, and a few degrees is enough to lose signal. On the coast there is a slower second enemy: salt and humidity corroding connectors and letting water into the cable over the years.
Problems very often appear right after storm season. If there has been a serious blow or a gota fría, the aerial is the first suspect. On the other damage storms leave behind, see protecting your installation from storms.
The amplifier
Most installations have one. It is an electronic device plugged into the mains and, like any other, it fails. The classic symptom is everything disappearing at once, at every outlet.
The downlead
Coaxial cable ages, especially the external run exposed to sun and rain. Decades-old cable can be throwing away a good part of what the aerial actually receives.
Mine or the community's?
In a block of flats the boundary is fairly clear:
- The community's: the aerial, the mast, the amplifier and distribution up to each apartment's door. Communal installation.
- Yours: from your own outlet inwards, including the sockets in each room and the lead to the television.
The quick way to find out: ask a neighbour. If several people have the same problem it is communal, and it falls to the administrator to arrange the inspection. If you are the only one, look inside your own flat.
If the community is going to intervene, it is usually a good moment to review the whole thing rather than patch it: telecoms installations in older buildings have a lot of years on them. Same logic we apply to replacing the door entry system.
What it usually is not
The television. If it fails on several different sets, it is none of them.
Rain, by itself. An installation with decent margin shrugs off a downpour. If yours pixelates every time it rains, rain is not the cause: the signal is so marginal that anything tips it over.
An off-the-shelf booster. Amplifying an already degraded signal amplifies the noise with it. If the real problem is failing cable, a new amplifier will not fix it.
Frequently asked questions
Why does my TV pixelate or lose channels in Spain?
It is almost always a signal problem rather than the television. TDT (Spain's digital terrestrial television) is digital: either enough signal arrives and the picture is perfect, or it arrives marginal and you get pixelation, audio dropouts and channels that vanish. The usual causes are a misaligned or damaged aerial, a failed amplifier, degraded coaxial cable, or a worn wall outlet.
If it only fails on one television, what does that mean?
That the problem lies between the distribution and that particular outlet, not at the aerial. If the other televisions in the property are fine, the aerial and amplifier are doing their job. It is usually the cable to that outlet, a splitter, or the wall socket itself.
Should I retune the television?
It is the first thing to try when channels disappear suddenly but the remaining ones look perfect, because broadcast frequencies change from time to time. It is free and done from the television's menu. If channels are still missing or pixelating after retuning, the problem is signal rather than tuning.
I live in a block. Is this mine to fix or the community's?
It depends where the fault is. The aerial, the amplifier and the distribution up to each apartment's door are communal installation and the community's responsibility. From your own outlet inwards is yours. A quick test: ask a neighbour. If several people have the same problem, it is communal.
Can storms damage the aerial?
Yes, and it is a common cause here. Strong wind knocks the aerial out of alignment or loosens the mast, and near the coast humidity and salt corrode connectors and cable over time. Signal problems very often appear right after the autumn storm season.
Still not getting a clean picture?
VLR Instalaciones has spent more than 20 years working across Málaga and the province, including aerials and telecommunications, as authorised installers. We measure the signal at the outlet and at the aerial, find where it is being lost, and tell you whether the repair is yours or the community's. Get in touch for a no-obligation check.