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Discussion Starter · #1 ·
Sorry if my puncuation and paragraphs are messed up. I'm not too good at that.

Do any of you know what can get rid of "humbars"? I've asked this

question before but didn't really get much help. I just wanted to know

if there was a device I could buy to get rid of this? One guy responded

below.

His response:

First I had to think who/what you/this are/is!

Now that I did, I find it hard to believe it is just the TV, but it

could be because a bad cap is a bad cap in any power supply (if that is

what it is). You are saying with just the TV powered, with nothing other

than a video recorder hooked up you see the hum bars? Do you have a

camcorder that you can hook into a video input? If so, do so and cap the

lens, then look at the pix, turn the brightness up some enough to see a

dark grey and see if the hum bars are still there. If so it is the TV or

a real problem with your AC service into your building/house!


My response:

I have this problem with the cable, dvd, and xbox. I've unplugged

everything from the T.V. and have used every socket in my apartment

using an extension cord and its still there. Hopefully its just the

Panasonic but as I said before, the Circuit City service guy said this

was a common problem with other T.V.'s as well. Please tell me more

about this "ground loop". Can this be fixed? The rolling bars are very

slight butvery noticable. When I'm watching my digital cable, dvd, or

xbox I can notice them from 8 feet away. The best way to explain what it

looks like is if the whole screen is black theirs about 20 or so lighter

black bars that are about 2 inches apart that roll up the screen. Oh

well, I guess I'll call my electric company and ask for an electrician

to come out to make sure my plugs are properly grounded or if theres any

noise in them or something. Any suggestions would be appreciated.

Thanks


I think I've answered my own question. I did a quick search at google

(eliminate hum bars) and came up with www.elect-spec.com/faqgrdl.htm.

They sell a Isolation Transformer and a Voltage Regulator. I'm not too

sure which one I need yet or if that site sells what I need but I'll

find out sooner or later I guess. They also sell a Cable Isolator but I

dont think that I need that because the problem occurs when nothing at

all is hooked into the T.V.. I hope that I don't need what they sell

because the cheapest thing is $400. Please help!!


Again, the problem I'm having is deciding what to get an how much they usually cost
 

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This is the short on hum bars,


If there is absolutely nothing connected to the TV and you get hum bar, then you most like have a bad electrolytic capacitor in the TV that is bad in the power supply section. Otherwise, you have a ground loop problem from one or more of the devices that are interconnected.
 

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Discussion Starter · #3 ·
Thanks for the response. Is there any device that will correct a ground loop? If so, do you know what the device is called and how much it costs? Also I didn't understand what you meant by "from one or more of the devices that are interconnected". Devices that are interconnected? What devices and what do you mean by interconnected?

I'm going to try to plug in my old 20" to see if it also has Hum Bars.
 

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Here is an excellent reference about Ground Loops, http://www.cinemasource.com/articles/gnd_loop.pdf

Yes, there are devices to correct for ground loop.


Interconnection is any wires connected between equipment(s).


Excellent idea, swap out the TV and see what you get.
 

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Just to clarify: When you said everything was unplugged from the TV, did you also disconnect the cable TV and/or antenna?


If not, you could have a ground loop problem from the cable TV entrance ground not being connected directly to the electrical ground that serves your circuit breaker box.


If so (cable or antenna disconnected), you likely have a power supply problem inside the TV set that external equipment would not necessarily help.
 
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