Kitz Forum
Chat => Tech Chat => Topic started by: Chrysalis on January 01, 2020, 10:36:51 PM
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Something I observed today, I noticed it for a while but never knew the cause before.
My TV is plugged into the same power extension as my fridge, its a bog standard extension with no isolation of each individual socket.
Every time the fridge starts cooling, the TV briefly loses its signal, I see the resolution and refresh rate as if I had just changed channels and a black screen for a second.
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My PC monitor used to blink off and back on again with my old fridge, plugged into a different outlet.
I was never sure if it was RFI over the mains or interference with the video signal.
I have surge protectors in several outlets, not even sure if they help but its worth a try as if its an actual power surge it could damage the PSU in your TV.
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May be wrong, but I thought the user manuals for fridges tend to say “do not use with extension leads”.
Guessing really, but one reason might be that the current surge when compressor starts might overwhelm a typical extension lead, leading to momentary voltage drop at the socket outlets.
You could try replacing the extension lead with a high-end one with extra thick cables, which might help in above scenario. But my worry would be, since appliance fires are in the news nearly every day, if the manual says not to do it and a fire broke out, even if unrelated to this, what would insurers say if you’d ignored the user manual?
Emphasise again, I may be wrong, fridge manuals may not all say “do not use extensions”.
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Yeah I will look into see what I can do, the fridge is in an awkward spot but most likely I will move the TV plug to use another power outlet.
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Agreed. It could be copper simply isn’t thick enough, so you get a voltage drop because of the lead’s resistance. Need to have a thick copper path all the way to the source. Or it could be interference; the fridge motor is arcing / spitting out wideband rf when the motor kicks off.
As you say, if the tv still has the problem when near to the fridge but on plugged directly into a wall socket then that suggests the latter, rf over airwaves.
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turns out its in its own outlet. (the fridge). So I guess poor isolating in socket power cabling?
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Not impossible, but pretty unlikely imho to be a house-wiring fault. Alternatively, the fridge compressor will naturally tend to create interference, and the TV signal has to compete with it.
Possible then, that the TV signal is simply weak, and the fridge is the last straw?
Or, the fridge will have components intended to suppress interference. Might that suppression be faulty?
One practical suggestion... modern fridges will have a moulded mains plug, which can be assumed to be good as internal connections are machine-crimped. If yours is older, or has ever been modified, and has an old fashioned plug that can be taken apart... take the cover off the plug and ensure all terminals are screwed down tight?.
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You think a compressor is able to interfere with a wired HDMI signal?
Also its IPTV I am watching so not a signal as such if you meant external. Plus I know from the recordings I make the actual content is fine, the issue is the picture on the screen been interrupted when the fridge switch's.
The fridge isnt brand new, but its also not ancient, plug is certainly not modified.
Before I look into a possibility of a fridge fault I will probably see if I can move the TV to be sourced from a socket at other side of room.
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You think a compressor is able to interfere with a wired HDMI signal?
Also its IPTV I am watching so not a signal as such if you meant external.
No, not likely for a compressor to interfere with HDMI.
I’d been believing all along we were talking of a Freeview broadcast, as you mentioned a TV losing its signal, this is the first time you’ve mentioned IP... :)
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In my extension to my home, I notice that if the lights are on and I turn the hoover on, the start up surge causes the lights to flicker. I know that the cleaner has a 1.5kw motor, which is much higher than a fridge motor. But like the starter motor on a car engine, the motor presents a very low resistance initially........
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No, not likely for a compressor to interfere with HDMI.
I’d been believing all along we were talking of a Freeview broadcast, as you mentioned a TV losing its signal, this is the first time you’ve mentioned IP... :)
Yeah sorry.
To clarify its the signal from the set top box to the TV been lost, not the actual TV signal.
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No, not likely for a compressor to interfere with HDMI.
I’d been believing all along we were talking of a Freeview broadcast, as you mentioned a TV losing its signal, this is the first time you’ve mentioned IP... :)
I'm not convinced, as in my case it WAS the signal over HDMI that would cut out. I don't think it did it once I switched to Display Port.
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After moving the TV to another power outlet the problem is gone.
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After moving the TV to another power outlet the problem is gone.
Good to all is now well. :)
I can offer no explanation but, for my own curiosity, will enjoy pondering the various factors when/if I have an idle moment.
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I can offer no explanation . . .
Likewise. :)
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High resistance contact between the plug-pins and the socket terminals ??