TV turns off when other appliances are switched

[Sparky Brian]

Hi all, I've came across a new one to me today and was hoping that someone else can point me in the right direction.

My customer has a newish flat screen TV that switches off then back on when various appliances are switched. I've not done any actual testing except to verify that the voltage is 240 and said appliances are on the same circuit i.e. the separate lights and cooker circuit do not affect the TV. His livingroom is on with the kitchen and the house is about 20/25 years old and is protected at the dB by an RCD which isn't affected.

I've searched the forum but couldn't find anything similar to this problem but if I've missed it I'd appreciate a link.

ps it's NOT the TV as customer has swapped with an older model and the same problem occurred.

 

[ProDave]

I would be doing a thorough test of the (presumably) ring final that the tv and other things are on.

If it's not the tv, then it sounds to me like volt drop due to the switch on loads of appliances.

Start with end to end resistance of the ring final. I suspect a lose connection somewhere giving excessive volt drop.

Did you measure the voltage with no load, or with a big load (kettle, toaster etc) turned on? and did you measure at the tv socket?

 

[apprentice87]

Why not just measure the circuit impedance [phase/neutral] at the telly socket, bit of ohms law, and you will have your answer..

john..

 

[Revved Up Sparky]

Sounds like a bad neutral to me

 

[Evans Electric]

Could be as simple as a loose connection before the TV , add a sudden load , it misses a beat and the TV shuts off .

 

[Sparky Brian]

Thanks for the answers lads and no I've not done any testing on the circuit at all yet but did say to the customer that it could well be a loose connection somewhere on the ring final. I'll arrange a day to go over and carry out the tests and I'll make sure I pop back on here to say how I got on. Cheers again for the input lads, appreciated

 

[Theorysparky]

Why not put a socket tester in the tv socket and listen to it when you swith the other appliances on

the tones should tell you whats going on

 

[Sparky Brian]

Thanks for the pointers lads, I finally got back over today and here's what I found.

Ring Final end to end > Live> 0.36 hms Neutral 15 hms :shakehead

Loose connection found on the Spur feeding the Under counter fridge, tightened it up and retested back at the board. The Neutral end to end was now the same as the Live at 0.36 hms

It certainly stopped the fridge from cutting out the TV but lo and behold the oven still turned the TV off when it was turned on and off

Anyway out came the oven and off with its back to check for any loose connections or loose spades etc.

Nowt :wacko:

Eventually disconected the fan, which was kicking in every time the oven was turned on, and Wallah No TV cutting out !!!

2nd fault found and job done ! So thank you all again for your input and if this helps some other Spark who gets a similar fault then he'll be as happy as I was as I loaded my tools and kit back into the boot

 

[m4tty]

Thanks for the update mate

 

[Doc Hudson]

Thanks for the pointers lads, I finally got back over today and here's what I found.

Ring Final end to end > Live> 0.36 hms Neutral 15 hms :shakehead

Loose connection found on the Spur feeding the Under counter fridge, tightened it up and retested back at the board. The Neutral end to end was now the same as the Live at 0.36 hms

It certainly stopped the fridge from cutting out the TV but lo and behold the oven still turned the TV off when it was turned on and off

Anyway out came the oven and off with its back to check for any loose connections or loose spades etc.

Nowt :wacko:

Eventually disconected the fan, which was kicking in every time the oven was turned on, and Wallah No TV cutting out !!!

2nd fault found and job done ! So thank you all again for your input and if this helps some other Spark who gets a similar fault then he'll be as happy as I was as I loaded my tools and kit back into the boot

Thank you for the update on this thread. I think this perhaps illustrates the importance of checking circuits before re enrgising. I assume the person who last worked on this ring simply did a fix switch on and run.

Doc H.

 

[ProDave]

...

Eventually disconected the fan, which was kicking in every time the oven was turned on, and Wallah No TV cutting out !!!

2nd fault found and job done ! So thank you all again for your input and if this helps some other Spark who gets a similar fault then he'll be as happy as I was as I loaded my tools and kit back into the boot

So did you replace the fan?

Disconnecting it may prove it's a faulty fan, but leaving it disconnected is not "job done"

 

[Steve3948]

Thanks for the pointers lads, I finally got back over today and here's what I found.

Ring Final end to end > Live> 0.36 hms Neutral 15 hms :shakehead

Loose connection found on the Spur feeding the Under counter fridge, tightened it up and retested back at the board. The Neutral end to end was now the same as the Live at 0.36 hms

It certainly stopped the fridge from cutting out the TV but lo and behold the oven still turned the TV off when it was turned on and off

Anyway out came the oven and off with its back to check for any loose connections or loose spades etc.

Nowt :wacko:

Eventually disconected the fan, which was kicking in every time the oven was turned on, and Wallah No TV cutting out !!!

2nd fault found and job done ! So thank you all again for your input and if this helps some other Spark who gets a similar fault then he'll be as happy as I was as I loaded my tools and kit back into the boot

But why would the oven fan force the TV off, the loose connection I can appreciate but unless the fan was tripping RCD or MCB I don't see how unless it was a Frequency thing ?

 

[Sparky Brian]

m4tty, you're more than welcome :Welcome:

Doc H. I totally agree :Salute

ProDave, Thanks for your observation even though it was a 'wrong observation' :slap as I never said I left ANYTHING disconnected. :C I said job done in that the fault I was called in to fix WAS fixed to the customers satisfaction (and mine as it happens). FYI the customer is replacing his oven this weekend as he was planning to get a new one anyway as the one in situ is ancient. I've been asked to call back to fit said oven in on Monday

Steve3948, I haven't a clue as to why the fan was effecting the TV unless it was a loose connection in the fan unit itsef or maybe it was just the age of the fan as the oven was at least 8 year old. Maybe ProDave can help you with the answer to your question if he's not to busy nitpicking other posts :C :^O

Thanks again to all the helpful posts above lads :Applaud

 

[binky]

it didn't read well before roderick :coat just sounded like you run off having left duff cooker like a very naughty boy :coat :coat

the young uns won't know wtf I'm on about :slap

 

[Sparky Brian]

binky if you knew me you'd know that my running anywhere days are well and truely over :innocent

Now if you'd said 'sneaked off' that would be a different kettle of fish altogether :slap

 

[ProDave]

ProDave, Thanks for your observation even though it was a 'wrong observation' :slap as I never said I left ANYTHING disconnected. :C I said job done in that the fault I was called in to fix WAS fixed to the customers satisfaction (and mine as it happens). FYI the customer is replacing his oven this weekend as he was planning to get a new one anyway as the one in situ is ancient. I've been asked to call back to fit said oven in on Monday....

Maybe ProDave can help you with the answer to your question if he's not to busy nitpicking other posts :C :^O

Thanks again to all the helpful posts above lads :Applaud

Well you said you disconnected the fan, it stopped the tv turning off and "job done" so what else was I supposed to think other than you left a cooker with it's fan disconnected? The fan is there for a reason, usually to ventilate the inter cabinet space to prevent the sides of built in ovens getting too hot, and I didn't want anyone to get the impression it was okay simply to disconnect it.

Replacing the cooker is a good solution, but you didn't tell us that was happening.

As to why? It's a cr@p television that's over sensitive to external influences and almost certainly does not meet the requirements of the EMC directive, even though it may have a CE sticker on it.

 

[Sparky Brian]

Well you said you disconnected the fan, it stopped the tv turning off and "job done" so what else was I supposed to think other than you left a cooker with it's fan disconnected?

Well you could have thought 'Well done on tracing what must have been a tricky 'double fault' instead of simply having a pop saying that it wasn't 'Job done' keeping in mind what I was called to the premises for in the first place, as in the title of this thread :C

The fan is there for a reason, usually to ventilate the inter cabinet space to prevent the sides of built in ovens getting too hot, and I didn't want anyone to get the impression it was okay simply to disconnect it.

You must have different ovens up north than we do down in the central belt Dave as I've never came accross an oven description that has inter cabinet space :Salute

As for giving the impression it was okay to leave the fan disconnected but reinstate the oven I appoligise for that if that is the case. :blink:

Replacing the cooker is a good solution, but you didn't tell us that was happening.

I also didn't tell you I had a cuppa or two, went for a pee twice,popped outside for a ciggie a few times and closed my boot door once I'd loaded my tools and kit in it either as I didn't see it relevent in the context of this thread. I will try harder next time though :innocent

As to why? It's a cr@p television that's over sensitive to external influences and almost certainly does not meet the requirements of the EMC directive, even though it may have a CE sticker on it.

You're probably right Dave as the TV in question is a new Samsung LE46B750 that my customer had just paid over £500 for but I'll certainly pass on your thoughts about that to him headbang

 

[Marvo]

I'm glad the problem is fixed but I can't help thinking you've treated the symptoms and not found the root cause. That said I've been thinking about this fault and I can't for the life of me come up with a satisfactory reason that an oven fan would cause a television to stop working.

I have a question or two though, is the television receiving an analogue signal from a terrestrial antenna? Is there an amplifier on the coax cable? What other signal inputs is the television receiving ie sky box, DVD machine, cat5 ethernet, etc

 

[Sparky Brian]

I'm glad the problem is fixed but I can't help thinking you've treated the symptoms and not found the root cause. That said I've been thinking about this fault and I can't for the life of me come up with a satisfactory reason that an oven fan would cause a television to stop working.

Marv, I can only think that it was some kind of radio/ interference signal that the fan was emitting that caused the TV to switch off. I'm afraid it will need to be a better man than me to answer that question but to be honest I'm not going to lose any sleep over it as electrically the Ring Final tested out perfectly and the customer is changing out the offending oven.

I have a question or two though, is the television receiving an analogue signal from a terrestrial antenna? Is there an amplifier on the coax cable? What other signal inputs is the television receiving ie sky box, DVD machine, cat5 ethernet, etc

TV is new, a Samsung LE46B750 with no council telly input but is hooked upto Sky and a DVD player and the sat cable into the sky set top box is no where near any electrical cables along it's entire run. Hope that helps but to be perfectly honest I'm just glad I found out the cause and eliminated them, or if you prefer took them out of the equation, for the customer

Best of it is the customer is an IT expert at a very big assurance company and he was stumped as well LOL