Plasma tv interfering with DSL connection. Please Help

Hi there, i am new to this so please be gentle lol.
My DSL connection keeps dropping everytime i switch my plasma tv on, this has only been happening for the past 6 days and i have had the tv a year, and the same wireless router since 2007. I have been and bought a new router which makes no differance what so ever and moved the router to the other side of the house which makes no difference too. I was wondering if anyone would know if buying a power conditioner would make any difference to this. It would be greatly appreciated if anyone could help or who has had the same problem.

What else has changed?

It could be that the background noise on the line has changed significantly and that the additional EMI/RFI from the television is enough to cause a loss of sync, OR the television has an internal problem and is causing a lot more EMI.

The EMI is probably radiated rather than conducted and a power conditioner is unlikely to make any difference.

Where does the phone line run?

Can you get the router stats for the line with television off, just after switch on and a few minutes later.

Might also be worth getting Router Stats Lite, set the sample time as low as it can go and run that whilst turning the television on and seeing how the SNR jumps around.

Edited by MHC (Wed 25-Jan-12 09:11:10)

If you have any phone extensions then try the modem from the test socket under the removeable faceplate on the master socket.

If that works then fit an ADSL faceplate.

Another option is you have diy phone extensions using flat cable replace it all with CW1308 spec cable, the twists help to reduce the effects of interference

hi there, thank you for replying. I will state i am not that up on computers etc so need things explaining in simple terms lol. The only things that has changed back in Nov last year i bought a sony 3d surround sound system, the Dsl light and the online light stays on while the surround sound is on. Within 3secs of turning the TV on the Dsl light flashes and goes off and the online light too. The phone socket is behind the tv along side the hdmi cable for the sky, i have no phone cable plugged into the sky. I have plugged the router into the test socket behind the faceplate on the wall, and the Dsl light stays on but router will not go online.

Almost certainly there is a large amount of radiated Electro Magnetic Interference or Radio Frequency Interference (EMI / RFI) being created and that is reducing the headroom the DSL signal has - referred to as Signal to Noise Ration (SNR) or how much greater the signal is than the background noise. If the SNR drops too low the modem cannot hold sync and will drop out.

Your first move should be to disconnect EVERY connector on the TV, Sky box, Sony Surround Sound, Speakers, DVD player, Amplifier &c and I mean EVERY one. And then refit all of them ensuring they are fully home. A connector with some corrosion can be a source of interference.


How long is the cable from socket to modem - and what type is it?

hmmmmmm i am not sure what kind the cable is but that has been replaced with a new one since i have been having problems and i have done the same with the filter too. The cable is approx 2 metres long. I have removed every cable the other day from my appliances, but i will do it again and see if i can come up with anything.

Is the phone socket a master or extension?

Having removed and replaced cable sonce - no need to try again. It was to ensure ALL were firmly installed.

Can you get a long, twisted pair, phone extension and try te modem well away from the TV?

Master. the Tv is at one end of the house and my bedroom at the other which has a phone socket in too, so i tried it in there, the self same thing happens when plugged in there, so thats why i havent bothered with an extension because i didnt think it would make any difference, with it not even working in the bedroom.?

You are right ... and have tried most of the simple things!

Is the ring wire connected from Master to Secondary? Wire on terminal 3. If it is, remove it at both ends.

After that, you need to start looking at RFI issues and that is a black art! I would start looking at moving the TV away a meter or so. Try again, DSL works then it is radiated RFI, if DSL fails could be anything. Try at 2m and see what happens. If it is caused by radiated RFI then put a sheet of aluminium foil between TV and router and try again.


What may have happened is a component in the TV has failed or partially failed but not so that it can be seen does not cause the TV to fail.

Sounds like the TV or electrical supply (or plug/socket etc.) may be failing or having a problem.

Try running an extension lead from another part of the house (preferably from a different ring main - from the kitchen or upstairs perhaps) so the router and TV are on different circuits to see if that changes anything.

hi there, i have done all this and it makes no difference, it is the tv that is giving off a Radio frequency interference and LG say this is quite common and there is nothing they can do. Mint lol

If it hasn't always done it it sounds a bit strange and more like something is failing!?

Hopefully your TV will die soon and your broadband will improve

Move the television away from the phone cable? Possibly make a cage/screen from aluminium foil for the modem/hub (earthed) and see if it improves.

Move the master socket? Does the drop wire come onto the eaves? If so, get BT to move the master into the attic or an upstairs room and install a modem there and then run a single Cat5e to where you want the router.

The interference might be affecting neighbours too, and it is feasible that you could get an order to turn off the TV and remove it...very very rare, but it is something to consider, as are your consumer rights.

I think I might be able to help here.

I do allot of electrical experimenting and have experienced similar things happen to my router (resyning) from some of my experiments.

This particular circuit I was working on involved high voltage arcs and every-time an arc was drawn the internet connection would drop and the router would resync.

This might be what is happening with yours, basically circuits inside of consumer electronics are "joined together" using solder. Its a common thing for these solder joints to eventually crack from the heat inside of the TV. Every time the TV is on the air inside of it gets hot and the solder joint expends and contracts when the inside of the TV chasing cools. Over many cycles this can cause the solder joints to become cracked and a poor electrical connection is being made. And sparking/arcing occurs from the poor solder joint.

Now if this only happens when you turn the TV on it might be in an area of the circuit board that is only needed/draws more power at power on. Also does the display brightness randomly change slightly at all? As that will use a small HT inverter to power the back-light (around 600v-1kV if I recall, this is enough voltage to ionise air and give off a ton of electrical noise if faulty).

It could also be the outlet too, to test simply unplug the TV and plug in a lamp to the outlet and see if you can see the lamp flicker at all. If if flickers or dims then you have a bad outlet which is easily replaced. Just don't do this when you have an inductive load running such as a washing machine/dryer/vacuum cleaner as these can cause lights to dim slightly momentarily when they begin to spin, thus it would be an unreliable test. Or simply plugging the TV into a different outlet in the house would be fine for determining if the outlet is at fault.

We had a similar thing with the outlet that our kettle plugs into and after boiling water you could take the plug out of the socket and the neutral prong would be quite hot!

Not saying the TV is faulty, it could well be something else but its my thought's anyway!

Also what MHC is referring to might sound strange but having an earthed metal cage is called a "Faraday cage". Its the same thing as being inside of a car and having it struck by lightening, the electricity would travel through the cars metal body and then arc from the wheel axils and go directly to ground/earth. It is becuase that would be the least resistive path for the electricity to travel. Same applies to RF interference and more so becuase of the "skin effect" with high frequency's.

Sorry if this makes no sense!

Edited by deleted (Thu 26-Jan-12 19:32:12)

It's a big issue...

If it's cutting your broadband off, it's probably doing it to certain neighbours too.

So be considerate and either
a) move the TV
b) get it fixed or
c) move the router elsewhere

Your next move has got to be to talk to your neighbours and find out if they are having problems too ... it may not be a failure but could be a resync at slow speed of large numbers of errors. If so, then you MUST resolve the problem which as MrS alludes to could be a complaint to LG and the potentially trading standards as it is possible that the Tv is outside permitted radiated RFI limits.

I have the same problem.

Brand new tv bought yesterday, plasma, interferes with my broadband router.

This happens on 2 different routers. Didn't happen with my old LCD tv.
Doesn't matter where the router is in the house, it interferes.

I've contacted the television manufacturer who havent been much help.

In reply to a post by Angrydog:

I have the same problem.

Brand new tv bought yesterday, plasma, interferes with my broadband router.

This happens on 2 different routers. Didn't happen with my old LCD tv.
Doesn't matter where the router is in the house, it interferes.

I've contacted the television manufacturer who havent been much help.

Is it "Fit for purpose?"

Personally, I would complain and reject it.

In reply to a post by MHC:

In reply to a post by Angrydog:

I have the same problem.

Brand new tv bought yesterday, plasma, interferes with my broadband router.

This happens on 2 different routers. Didn't happen with my old LCD tv.
Doesn't matter where the router is in the house, it interferes.

I've contacted the television manufacturer who havent been much help.

Is it "Fit for purpose?"

Personally, I would complain and reject it.

It's going back tonight. Gutted as its a really nice tv

Has anyone asked Tommy if his problems started when he got a new TV?

If it was a very nice price too, then that might be one of the reasons.

Yeah it was, 330 + vat. It's been returned now, back to my 32" LCD rubbish! Lol

In reply to a post by gomezz:

Has anyone asked Tommy if his problems started when he got a new TV?

He said it started 6 days ago and the only that has changed is that he got a new surround sound system in November last year ... so a reasonable assumption that it is not a new TV.


and also found another post where he says he has had the TV for a year.

Edited by MHC (Fri 27-Jan-12 21:45:28)

i HAD the same problem....heres how i fixed it....and it was easy! the problem had NOTHING to do with my router........it was the wiring. i knew this cause my local network still worked when the tv was on....just no internet cause it knocked out my DSL modem.........heres how i fixed it....

its a new 51" plasma 3D smart tv samsung. i have DSL and i noticed that when the TV was on, the DSL didnt work.....or was extremely slow. the plasma tv replaced an lcd and i never had this issue with the lcd.....i narrowed it down and it was definitely the TV. i thought maybe the tv was causing some kinda weird electrical issue with my modem so i tried running an extension cord from the tv to every other outlet in the house and the DSL still didnt work when the tv was on. the plasma tvs are known to interfere with DSL because they give off RF. so after i tried that i figured the problem had to be radiated RF from the tv or screen itself. so i went into the attic and saw that the phone lines not only run directly above the tv, but that it was wired with old-ass flat wire. so i went and got cat5e cable and went into the attic and re-routed the phone lines and cut off the flat cable, replacing it with the cat5e.....instead of just replacing the wire, i routed it around where the tv is also so that the wires were as far away from where the tv is as possible. spent nearly 2 hours sweating my ass off in the attic and viola!!!!!! FIXED!

turns out the high level of RF the tv gives off added to the fact this place was wired with ancient wiring.......the old wires were just a huge RF antenna. the cat5e is coiled and is shielded from RF and cross-wire interference so it now runs great. and now the tv streams and all that where as before i couldnt even get it connected to the internet for obvious reasons...TV on=no internet.

DONT ditch the TV! its the wiring! you might even be able to just pick up the existing wires and lay them away from the ceiling of the room where the tv is if theres enough slack. but if you have the old flat wiring...get a spool of cat5e and either replace the wiring completely...or just splice it in above the room where the tv is adding enough slack so you can put some distance between the tv and the wire. worked for me! now im a happy 3D plasma smart TV streaming fool!!! hahaha

Edited by deleted (Sat 19-May-12 06:17:49)

i HAD to reply because when i first had this issue and googled it....this was the first place that came up.....i had even asked a guy at an electronics store that sold these tvs about this and he had no clue.....so i had to join just to post how i solved my issue.

HOPE THAT HELPS YOU AND ANY OTHERS WITH THIS SAME ISSUE. PEACE AND HAPPY PLASMA TV VIEWING!!!!!!!!

Just shows how bad the RF radiation from plasma TVs is. If you had a friendly radio amateur living near you he would have soon told you what the problem was. Although you have cured your own problem, surely the real cure is for the manufacturer to sort out the TV so that it doesn't radiate RF in the first place. Some manufacturers, especially Panasonic, are very aware of this issue and will address these problems, provided you find the right person to speak to. Obviously your local TV dealer or chain store won't be aware.