No DVB Signal

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It could be coincidence, but on Friday night, we had a thunder storm that was pretty much overhead. Since then, I had no signal on nearly all the freeview channels and the one or two that I did have, were terrible - pixelating, stalling, crackling.

I followed the "reset" instructions from Freeview (unplug TV, unplug aerial, turn TV on, retune with no aerial to reset it, then plug in the aerial and retune).

I've done that and now it's showing no DVB service available.

I've taken the aerial out of the splitter and booster and put direct into the TV - done all that again - still nothing.

My mum has given me a loan of an indoor aerial to try and at least this time, channels started showing up on tuning - but when you go to the channel, it's still saying no signal.

I wondered if it was the TV but I've got two TVs and two DVD recorders and they're all doing the same.

Anyone got any ideas please? I know there's normally naff all on the TV to watch, but it's nice to have the choice not to watch it lol
 
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I contacted Freeview and they said that there's no transmitter faults.

None of my neighbours are in - there are four of us in the block and I can see three aerials - I've no idea which one is mine :/
 
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Have you other neighbours around, apart from the four?

It sounds as if you are maybe in a fridge area, with a poor signal, where an outside antenna is essential - maybe why the indoor would not work.
 
There could be a couple of different points of failure after and electrical storm. Trouble-shooting your system is a good idea, but in unplugging the booster and splitter you may have actually unplugged the power supply feeding a masthead amplifier. Whilst unplugged, you'll get no signal from the aerial cable directly because it's being blocked by the masthead amp that has no power.

Also, unless you know from previous experience that the particular indoor aerial has work in your home - and in the room where you're using it - and also that it's correctly aligned both in direction (i.e. pointing at the transmitter) and in polarisation (i.e. the 'fins' either horizontal or vertical to match the polarisation of the local transmitter) then it could be giving you a bum steer too.

You'd be better off taking a TV and a Freeview recorder to your mum's place to try on her aerial system. That way you know 100% for sure that there's a signal. After you've tried an auto tune then you'll know if your telly and recorder are good. Then you can go back home and start to diagnose where the fault is with the aerial system.

Presuming that the TV and recorder work, and there have been no lightening strikes within a mile or so of your property, the next thing to do it to try the single aerial feed. For this, you'll need to know whether you have a masthead amp, and if so, make sure that its power supply is connected.

A masthead amp is generally a box fitted somewhere along the length of the aerial mast. It looks something like this:

mastheadamplifier.jpg


image credit to www.digitaltvhelp.com.au



The power supply for a masthead amp is often mistaken for a booster because it plugs in to the mains and has an In and an Out for aerial connections. The exact look varies from make to make, but they all follow a very similar layout of signal connections and a power lead.

What it really does is use the aerial cable itself as the conductor for power up to the amplifier box near the aerial proper. In the trade, we call this phantom powering. That's because there are no extra wires, and the power passes like a ghost unseen by the aerial signal travelling down the cable in the opposite direction.

When you come to test the aerial system, and you've seen that you've got a masthead amp, then you'll need this connected so that the amp works otherwise there'll be no signal.

s-l640.jpg



These sort of power supplies don't just power the masthead amp. They can also power a certain class of distribution amplifier that uses phantom power too. This means that if you're struggling to find how the 4/6/8/12-way amplified splitter in your loft connects to the mains, then it might be that it uses phantom power. If it does, then it may be that the coax connection from the power supply needs to connect to a specific socket on the amp, so do take the time to label your connections before unplugging things.

With the aerial, masthead amp and its power supply connected then you should get a signal so long as there has been no damage or misalignment.

A multi-way amplified splitter can be reconnected after you've proved that the basic aerial system works.


In the event that the basic test didn't produce a signal on a TV or recorder that you know is good, then you're looking for faults in the aerial system.

Start with the power supply. There should be an LED light to indicate power. If there's no light then do the basic checks first: Is the wall socket switched on. Has the fuse in the power supply's mains plug blown? If there's still no light then chances are that a mains surge could have killed the power supply. Buy a new one.

Once the power supply is running, double-check any aerial connection leads. Stray wisps of shielding braid touching the centre core will prevent the masthead amp getting its power. A storm won't change that or create that as a problem, but once you start to mess with connections then if plugs are loose or were poorly fitted it may become an issue as things are reconnected.

Things that could still stop the aerial system from working: 1) a head masthead amp 2) a fried circuit board at the back of the aerial called the balun. Since both of these are up at the aerial level, then you'll need to access the loft or eaves or roof where ever the aerial is fitted. That might be a job for an aerial fitter.


If this or any other reply was helpful to you, then please do the decent thing and click the T-H-A-N-K-S button. It appears when you hover the mouse pointer near the Quote Multi-quote buttons. This is the proper way to show your thanks for the time and help someone gave you.
 
Thank you so much.

I have a bit of an update - I've had my niece standing on a chair with the indoor aerial held up and kind of pointing in the right direction and lo and behold, we got a few channels - not many, but better than none. I realise that will be because 1. the transmitter it's pointing to isn't a main transmitter and 2. it's clearly not in the right position - but I think it points to the fact that it is my aerial that's the problem.

I don't have a loft as I have an upstair's neighbour, so it'll be the aerial man on the roof :). I could be wrong, but I think it's just an aerial, comes into the house and goes into a separate booster, which then goes to a splitter to run the other TV.

The lightning was pretty close - it was actually lighting up my living room which I've never seen before. At first, I wondered if it had struck the aerial, but then sense prevailed that if the aerial had been struck by lightning, half my house would probably have been blown away along with every electrical appliance.

I'll see if I can see if the aerial has an amp on it but with three aerials up there, I'm not sure which one is mine.
 
The lightning was pretty close - it was actually lighting up my living room which I've never seen before. At first, I wondered if it had struck the aerial, but then sense prevailed that if the aerial had been struck by lightning, half my house would probably have been blown away along with every electrical appliance.

It doesn't need to be a direct strike to do damage to electronics just in the area is enough. I suffered some expensive damage following a church tower strike, 100 yards away, which also took out lots of phones too.
 
It's probably just coincidence but I'm glad I wasn't outside when it was striking.

The biggest downer is that the only channels I can get are channels that I would never watch lol

I am however, all sorted with a phone number for an aerial man to phone in the morning.
 
I followed the "reset" instructions from Freeview (unplug TV, unplug aerial, turn TV on, retune with no aerial to reset it, then plug in the aerial and retune).

NEVER EVER EVER retune when you lose signals, as you just wipe the memories, as you have discovered, so when get the signals back you don't know.

Those Freeview reset instructions are so wrong.
 
NEVER EVER EVER retune when you lose signals, as you just wipe the memories, as you have discovered, so when get the signals back you don't know.

Those Freeview reset instructions are so wrong.


According to Freeview, that's what you need to do - wipe it completely in order to restore it :(
 
According to Freeview, that's what you need to do - wipe it completely in order to restore it :(
They're right in so far as refreshing the TV's tuning.

I can see the point that Winston was trying to make. It's that in a situation where it isn't clear if the TV or aerial is at fault, retuning makes things a bit more difficult. Only retune once you're sure you're getting some channels.

In the end it's not a complete disaster. So long as a person knows which is their local transmitter, then it is possible to manually tune 2 or 3 mux channels. There are Web sites that list transmitters by house post code. TV user manuals are often available online. I'm not saying that it's easy, but neither is it beyond the capability of the average person either. :)
 
According to Freeview, that's what you need to do - wipe it completely in order to restore it :(

As I said those instructions are SO SO WRONG.

NEVER EVER EVER retune when you lose signals, as you just wipe the memories, as you have discovered, so when get the signals back you don't know.

Why Freeview persist with this wrong information I don't know.

I once contacted Freeview over a transmitter outage and the first thing they said was had I retuned. I said absolutely not and told them why. After checking they actually discovered the transmitter was down. (Ventnor).
 
I must admit, having chatted with Freeview and done everything they said, when I said it still wasn't working, the answer I got was oh well, sorry I couldn't have been more help.

I've discovered another 4 aerials on the other side of the chimney - one of them does have a box like Lucid showed in the picture but I'm none the wiser as to which aerial is mine. I'm assuming that the old aerials pre Freeview are still up there. Got an aerial man out tomorrow which means just another night of having nothing more than channel 4 to watch.
 

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