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I have my computer connected to my TV via HDMI. Every time something electrical happens (fridge turns on, stove sparks, etc), the image on the TV goes black for a second and then comes back on. And before anyone asks, trust me, I checked other options, it is perfectly in sync with the fridge/stove/etc and not some random coincidence

Anyone have any ideas as to what is causing this or how I fix it? Or should I just get a new HDMI cable?

The lights do not flicker or dim when this happens.

Also, if it is on the same circuit, how do I figure that out?

And will connecting the TV to a regular surge protector work, or do I need to put it on a voltage stabilizer?

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  • My TV does this when the furnace kicks off! I bought a big UPS unit in hopes to fix this problem! However... It just did it again! It took a few days before happened again! Also, if I unplug power to the ups and plug it back in, the TV flickers when power is restored to the ups! Ugh... – user31428 Jan 7 '15 at 6:15
  • I had this problem with an LCD monitor that would appear to reset every time a light switch was used--fwiw a UPS did not help, but a thicker, shielded HDMI cable did. – Tahlor Feb 7 '18 at 18:46
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When the fridge turns on (some) and when (some) ovens start their capacitors pull a ton of current to start the motor/function needed.

If these are on the same circuit as your TV this is a pretty big issue and the fluctuations could cause damage to your TV circuit board over time.

Even if these aren't on the same circuit your TV is getting a voltage fluctuation from the main circuit. Your TV having intelligence built in probably has its own way of handling these fluctuations - with one turning off some extraneous functions... like HDMI working.

HDMI cables work or don't. If yours is showing a picture then getting a "better" one won't help.

What I would do? First make sure that your TV is not on the same circuit as the fridge and stove. In some places this wouldn't meet code and it certainly isn't good for the electronics.

If they are not on the same circuit then you may need to call the electric company and figure out if they have anything that is causing fluctuations on your line when something high voltage is plugged in. They may fix the issue or offer suggestions - and a lot of times this is free. If the electric company believes it is an issue on your side you will need to troubleshoot why you have this interference - usually a loose connection in the main box.

And lastly you may need to change appliances or tv... Not saying you have to do this but you gave a specific example. Your TV may not handle any kind of voltage fluctuation well. Whenever a major appliance turns on there will often be a little voltage fluctuation. Most electronics are built to handle this. Maybe your TV does not handle this well and your electricity issue is not really a big deal. Or maybe your TV handles this normally and this would happen with all/most TVs.

Question too - do your light flicker or dim during this initially engagement?

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  • On the extremely small chance it is the HDMI cable, get one with a lower gauge (bigger wires) and ferrite beads. – Jason May 19 '13 at 18:21
  • The lights do not flicker or dim when this happens. – merlinpatt May 19 '13 at 21:45
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    HDMI is electrical, it does not transfer "light." However, it is a parallel interface that is very sensitive to voltage drops, synchronization issues (there are many little wires in that cable), etc. Motors need to be on their own branch circuits precisely because of issues such as this: the spike of current to start the motor can interfere with other devices or even trip a breaker if the circuit is shared. – user4302 May 20 '13 at 1:23
  • @John you are right. I had fiber on my mind. Either way all HDMI cables are basically the same - they work or they don't and this one works... – DMoore May 20 '13 at 4:35
  • @mike - go to your main breaker box and find the switch that shuts down the fridge, stove, or tv. Then see if they are all off when you flip the breaker. You may have to turn a few off (one at a time) to figure out what is on what breaker if nothing is labeled. – DMoore May 20 '13 at 4:38
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I agree with DMoore that the flickering is almost certainly caused by a voltage dip when a large appliance turns on. A fridge can easily pull 1000+ watts momentarily as the compressor starts.

If you want to verify the voltage dip you can do so with a multimeter with a "MIN" function. Insert the multimeter probes into the outlet that's giving you trouble, set the multimeter to "voltage (AC)", and enable the "MIN" mode, which will remember the lowest voltage it sees. Then wait for the fridge to turn on. Typical US household voltage should be in the 110 - 120 V range. A voltage dip much below 110V could definitely cause flickering.

If the devices are on the same circuit, the easiest thing to try would be putting them on different circuits. You could also call the electric company to see if they have any thoughts.

If you don't want to do any electrical changes, you could also get a voltage stabilizer to plug your TV / home entertainment system into. It's basically a fancy surge protector that will even out momentary irregularities in the household voltage current. Many battery-backup power supplies ("UPS") also include voltage regulation.

Edit based on question updates:

The same circuit means that the outlets run back to the same circuit breaker in your breaker panel. The easiest way to figure out if they're on the same circuit is to flip off the switch to the refrigerator and see if the TV also goes dead. If your circuits are not labeled, this may take some trial and error.

As for a surge protector: they won't help with under-voltage at all. Surge protectors cut the power when the voltage gets far too high (typically 300 V or more), but don't do anything when the voltage is too low.

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  • If it is on the same circuit, how do I figure that out? And will connecting the TV to a regular surge protector work, or do I need to put it on a voltage stabilizer? – merlinpatt May 19 '13 at 21:45
  • @mikepatt77: See answer updates. – Hank May 20 '13 at 1:14
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Also see What should I look for when diagnosing electrical circuit gremlins where load is much less than capacity?. I had pretty much the same sort of problem, and while the answer isn't pretty, it may be a train-of-thought option.

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Use some kind of line filter on your circuit connection to remove the electromagnetic interference (EMI). Sometimes they are called EMI filters or sine filters (for bigger appliances). They are produced as IEC inlet filters too (search for them).
They are based (mostly) on interference suppression capacitors, but can be quite complicated to filter out the unwanted EMI.

Even an AC line surge might help, maybe some of your friends might lend you some to give it a try.

Consult an electric installation shop to buy the best fit for you - it depends on voltage and amperage.

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Problem Solved. Plugged my TV into a Surge Protector and the cutting out stopped.

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