I have a very strange problem which may or may not be the TV.

The TV is plugged in to a surge suppressor with the rest of my home theater. Satellite box is also plugged in to the suppressor, including the coaxial input/output, so my system "should" be completely isolated and protected from any spikes.

Here's the problem: I have two lamps plugged into two separate outlets in the room, which makes a total of three being used (including my home theater). When I touch one of the lamps, "sometimes" the TV will very briefly lose the picture for a second or so, then comes right back on. I cannot always recreate this, as sometimes it happens, sometimes not. I've also had it occur when getting up from my sofa. The TV is on a wooden stand, and the floor is carpeted. Is it possible I have "dirty power" running in the room? I took a look on Wikipedia, and read up a little on Power Conditioners. Should I invest in one, or is it likely something else? I'm no electrical engineer, so if anyone knows what may be the cause, I'd appreciate your input.

  • The surge suppressor does not isolate your appliances in any way from the rest of your circuits unless it detects a serious voltage spike (usually 300 or 400V), and even then it will only absorb a limited amount of energy. Unless it's defective I doubt it's a factor here.
    – Hank
    Dec 13, 2013 at 3:12
  • 1
    ... many people think surge suppressors are magic devices that will protect against all problems, but in fact they only provide protection against a very limited set of circumstances. The spike needs to be high enough to trigger their crude mechanisms but not so much as to overwhelm them. And there are many other electrical problems that can occur without any voltage surge at all.
    – Hank
    Dec 13, 2013 at 3:15
  • Does the TV turn off, or is it just a blank screen? You have the coaxial cable, a TV, two lamps, and a home theater system, all connected to the surge suppressor. Is that correct?
    – Tester101
    Dec 13, 2013 at 11:03
  • What kind of television is it? If it's one of the newer flat-screens, you may be looking at one that's on its way out. My television seems to have the same behavior (no surge suppressor, though), and going by what I've read, it looks like the capacitors are on their last legs.
    – alt
    Dec 13, 2013 at 13:21
  • In addition to the other comments, keep in mind there is a difference between a surge suppressor and a line conditioner. Good surge protectors will do both, however, as will UPSes. Line conditioners are better at protecting from small differences in voltage, surge protectors protect against large (damaging) differences.
    – user4302
    Dec 14, 2013 at 5:19

3 Answers 3


Every cable/satellite installer I've ever talked to says "Do Not connect the cable line to a surge suppressor." I'm not sure how exactly these devices are designed, but for some reason they tend to degrade, interrupt, and/or interfere with the signal. The first thing I would try in this situation, is to disconnect the cable from the surge suppressor and connect it using a simple coaxial cable connector.

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NOTE: I am not a cable/satellite installer, I'm just some guy on the internet. I will not be held liable and/or responsible for any damage caused by my advice. Proceed at your own risk.


Invest in a new surge suppressor. Don't invest in a power filter: you don't need it, it won't help.

If you call for service on the TV they may require you take it off the surge protector: the protectors are so troublesome. Your surge protector does nothing at all to protect against power line noise: it's not designed for that. It may be of some use protecting against a residual lighting strike, when combined with a strong whole house SPD (surge protective device).

Plug the TV directly into the wall, and remove the coax connector, to see if the behavior changes.

Also figure out if the signal is lost for a second, or the power is lost for a second. Does the TV act like you unplugged the Cable/Antenna, or like you pulled out the plug?


My guess... Sounds like improperly grounded outlets or other wiring issue.

If your outlets have 3 prongs (1 for ground) get one of those plug in outlet testers. They can tell you if the outlet wires are correct.

It's a little three prong device that fits in the outlet like a regular plug and has 3 LEDs that indicate what the problem might be.

You can also check if you have a multimeter but it's more complicated and slower. They testers are cheap enough and very nice to have. Get one that also tests GFCI outlets so you have everything covered.

If you're outlets are the old 2 prong and you're using an adapter on the surge supressor then it should be one of the ones that has a wire that screws into the center screw of the outlet cover. Provided the box is properly grounded that is. That you'll need to check with a multi meter.

  • I agree this sounds like a missing ground or a ground loop or something. A outlet tester is an obvious starting point but they do not correctly identify some fault conditions like a ground/neutral swap or current on the group wire.
    – Hank
    Dec 13, 2013 at 3:09

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