Sky signal lost when appliances switched on. Help Me Please!

laylandiai · 30-10-2009, 4:47 PM

Hi,

What a nightmare, several sky engineer visits and I am no closer to resolving my issue. Whenever a household appliance is switched on, hob, microwave, washing machine, my sky signal disappears or the screen locks. My freeview is totally unaffected. I have been told by sky that the signal from the communal dish is pefect and nobody else in the block seems to be affected. I have replaced all leads and now on my 3rd box. At one stage the sky rf lead and the scart lead became so hot that they were difficult to disconnect allthough this did just happen the once. I hope somebody can give me some ideas as I am pulling my hair out, nobody seems to have any idea. It would be nice to be able to watch tv and have a cup of tea at the same time.

I'm new to this forum and have registered due to word of mouth and hope that someone can help me.

grahamlthompson · 30-10-2009, 5:00 PM

Quote:

Originally Posted by laylandiai

Hi,

What a nightmare, several sky engineer visits and I am no closer to resolving my issue. Whenever a household appliance is switched on, hob, microwave, washing machine, my sky signal disappears or the screen locks. My freeview is totally unaffected. I have been told by sky that the signal from the communal dish is pefect and nobody else in the block seems to be affected. I have replaced all leads and now on my 3rd box. At one stage the sky rf lead and the scart lead became so hot that they were difficult to disconnect allthough this did just happen the once. I hope somebody can give me some ideas as I am pulling my hair out, nobody seems to have any idea. It would be nice to be able to watch tv and have a cup of tea at the same time.

I'm new to this forum and have registered due to word of mouth and hope that someone can help me.

I would be inclined to have your electrical installation checked by a qualified electrician. The only way that the cables can get hot is if they are passing a significant current, this may be as a result of a fault on your system thats passing current up the coax cables to earth at the common earth bond. Passing a significant 50Hz AC current up the coax screen will swamp the weak sat signals.

laylandiai · 30-10-2009, 5:16 PM

I have to say my thoughts were electrical especially after having exhausted all other possibilities. I did call an electrician out a couple of weeks ago who said that the electrics seemed fine in the apartment. I am not sure what we should be asking an electrician to check. I am not at all electrically minded so please excuse my ignorance but is there any risk of fire or appliances blowing.

Trollslayer · 30-10-2009, 6:05 PM

Disconnect the dish earth and try again - it sound like your electrical earth bond is way off.
This will prove this dish and your mains earth are at very different potentials.

laylandiai · 30-10-2009, 6:13 PM

Thanks again, I live in an apartment block, we have just had the management company send an engineer who has replaced the multiswitch (i believe) in the cupboard upstairs. I assume that they would need to come out again to try what you are suggesting? I really appreciate your help with this, the problem i seem to have is that anyone who comes round either doesnt have a clue or doesnt seem to care about the issue. Would you mind trying to explain to me in basic terms what you belive could be causing this, i dont understand earthing etc.. sorry to be a pain.

SevloW · 30-10-2009, 6:54 PM

As your on your 3rd box and it is still happening that rules out the box being faulty. Have you tried plugging the mains lead for the Sky box into a different electrical outlet? There is no way your leads should be getting warm let alone hot.

laylandiai · 30-10-2009, 6:58 PM

The hot leads has happened twice now once with the rf lead and once with the scart. I can try the mains lead into another appliance to see however that particular symptom of hot leads is v intermittent. Is it likely that there is current running into the face plate in the wall where the sky input is or can you suggest any likey causes for the appliances just affecting sky and not freeview

J7MAN · 30-10-2009, 7:13 PM

As others have said, it sounds like the system is being back fed somewhere. Can you pop the faceplate off and check the back? Is it melted or charred anywhere.

I've had a situation before where a residents video was back feeding the system and melting the coax to one particular property, another engineer claims the flylead was arcing onto the radiator at one point too.

laylandiai · 30-10-2009, 7:16 PM

I'm going to check the faceplate now, i can see some charring on the sky input in the wall allready without removing the plate, what would cause this feedback, is there anything i can do to try to eliminate it.

SevloW · 30-10-2009, 7:17 PM

What I meant was can you plug the Sky box into a different plug outlet, sorry if I was not clear.

Edit - Looks like J7MAN has nailed the problem

laylandiai · 30-10-2009, 7:24 PM

I see, probably me not you. I can try that! At the moment it is plugged into an extension lead.

laylandiai · 30-10-2009, 7:28 PM

different mains socket and still getting the interference from appliances. I mean if i switch on 2 rings on the hob i get the message "no satellite signal is being received" and when i switch them off it returns immediately. This is driving me mad at this stage!

J7MAN · 30-10-2009, 7:31 PM

Quote:

Originally Posted by laylandiai

I'm going to check the faceplate now, i can see some charring on the sky input in the wall allready without removing the plate, what would cause this feedback, is there anything i can do to try to eliminate it.

The best thing to do really is get either a sparky or competent engineer to attack the multiswitch with a multimeter, see if there is any abnormal voltage coming down any of the other consumer cables.

laylandiai · 30-10-2009, 7:37 PM

Think thats sound advice, it does seem that it is just our appartment and the multiswitch has just been changed by the management company as they were assured this would rectify the problem. What is the link between the electrics into the flat and sky?

J7MAN · 30-10-2009, 7:42 PM

There's definitely something bad going on, checking the multiswitch will tell you whether it is a backfeeding issue or something local to your property. As for the why, you'd need someone with alot more expertise, probably someone part P regged.

laylandiai · 30-10-2009, 7:46 PM

Thanks for your help with this, I think your dead right, next port of call is get a spark out again to do some checks for me. I will add to this thread once he has been to update you on the situation. Thanks again.

J7MAN · 30-10-2009, 7:50 PM

No worries pal.

grahamlthompson · 30-10-2009, 11:22 PM

The symptoms you have clearly show that when you switch on an appliance that draws significant current then some of that current which should return on the system neutral is finding a return path by way of the sky coax connection screen to the earth bond. AV equipment is normally double insulated so the only earth point should be the safety earth bond at the feed from the quattro lnb on the dish to the multiswitch. This strongly suggests you have two problems one there is a coonection from the earth in your property to the sky box coax screen, this may be being provided by other equipment connected to the sky box. Disconnect everything but the coax feed to the box and the scart lead to the TV and see if the problem disappears. Secondly that the neutral return conductor from your installation has a significant resistance, this may well be in the supply box that has your main fuse belonging to who ever you get your supply from. If it was purely confined to the cooker I have seen red ring type hotplates continue working even with a burnt hole in the element with the current returning via the earth connection rather than the neutral. Does your installation have a dis board with a rcd trip ?