HELP! Ground loop isolation problem with my Plasma TV...

Hey everyone,
I have had a problem with my Panasonic Plasma TV for some time now. I have these pink and green lines that are barely visible that scroll slowly up the screen. SCROLL DOWN TO THE BOTTOM TO VIEW MY MAIN QUESTIONS

- The lines are horizontal and always move upwards
- The lines themselves vary in width but always scroll up at the same speed
- The pink and green colors are only slightly visible... as if I held up a strip of celophane in front of the screen and slowly started moving it upward
- I see the lines no matter if I am watching the DVD player, HD Television, or playing a video game
- The lines are easier to see at night...(although this might only be the fact that I can't get my rooms completely dark during the day time or the power for the lights could be the problem??)

Here are the things I did in order to try and fix this problem.
1. I talked to some people at Radio Shack who told me it is probably a "Ground Isolation Problem" so they sold me a 3-prong to a 2-prong power plug for the TV and the problem did not go away. (Although the TV was the ONLY thing that I tried it on...more in a second.)
2. I bought really expensive Monster brand $100 component video wires with heavy shielding for most devices hooked up to my theatre system. Then I seperated all the wires and untangled them away from each other but still no luck.
3. Then I unplugged all the nearby devices that could be producing any sort of interference like my powered sub-woofer, cable DVR box, 110 watt amp, DVD player, laptop... But still no luck.
4. Then a storm hit my house and fried out a bunch of things including my TV so here was my chance to send it to a shop and have it fixed. Since then, the repair shop has replaced color boards, digital boards, and a power supply for the TV costing (my insurance company luckily) over $1,500!! But still, I see the same problem with the green and pink lines slowly scrolling up.
5. So the repair shop is going to switch out all the parts again to make sure they did not cause the problem. While this was going on I decided to search the internet as deep as I could to find out if anyone else had the problem...here is what I found:

http://www.avsforum.com/avs-vb/showthread.php?t=793480
-This link talks about how other people have had the same problem, only to discover the entire time it was a "Ground Isolation Loop."

http://www.audioholics.com/tweaks/c.../ground-loops-eliminating-system-hum-and-buzz
-This link talks more about what causes a "Ground Isolation Loop"

So now I bought both the "Hum X" electrical Ground Isolation Hum Eliminator from http://www.zzounds.com/item--EBTHUMX for $55

and I bought the Jensen Cable TV Ground Loop Isolator from http://www.markertek.com/SearchProduct.asp?item=JEN-VRD1FF&off=0&sort=prod for $55

(I wanted to buy the same type of Video Hum Ground Loop Eliminator for the 3 RCA Component Video cables but that costs over $500!!! Yikes! So I'm just gonna get these 2 things and hope this works.)

Here are my questions:
1. Can I plug in the electrical Ground Loop Isolator into the wall socket and then split it? (Or more likely do I have to figure out what the exact devices are that are causing the hum and use that on each and every one of them?)
2. Are there any RCA component Video hum isolators out there under $500 because that price is insane.
3. I think the lighting rails in my house and especially in that room are the culprits. Is there any way to isolate them?

Just a thought, you say you bought a monster power cable, have you tried any of their monster power extension leads? They give you clean power and from what I can gather they're pretty dam good. A touch expensive though. Unfortounately I don't have a link apart from to the company that I work for (Comet group PLC UK based electrical retailer)

I would suggest that you check all of your chassis grounds on your components with two prong plugs. Maybe even run separate grounds from the chassis of each component.

Then starting with absolutley nothing other than the TV hooked up keep hooking things up until you find the problems. If the TV does it on its own try the 3 to 2 adapter and see if that fixes it. Then keep adding components until it returns, once you have found the problem properly ground it and you should be in business.

If its your lights you shouldn't have the problem when they are off.

From the links of the forums I provided and the other with the "expert" technical advice... They said that the video bar hum or audio hum is rarely caused by unclean power. Ground Isolation Loops are usually the cause because 2 different devices in your house can be grounded at different places which causes voltage on the system.

Example: My cable lines are grounded at the green pedastal in my back yard but my house is grounded to the power lines at the power box...or maybe the builder also installed his own ground like the water pipes??

By the way, what does your company do exactly? I always wondered exactly how those "Clean Power" module thingys worked and what they are usually made for?

Um Tommy,

Why would you of all people go for the “consumer sheeple/let corporate America dip in your wallet” approach to something that is so easily fixed? Seriously, do your self a favor and read my sticky in HTPC Multimedia myths exposed. ATM, I don't have anything in there about ground loops but I probably ought to.

Anyhow, a ground loop is pretty much what it sounds like. Good grounding should have a star, bus or tree topology. Bad grounding has a ring topology and you end up with a slight voltage differential. It can also be quite frustrating to track down the problem but when you do, you can often solve it without spending any money or at the least, very little money.

Let's say just for grins that your problem is in your signal cables somewhere. Now all of your components ought to be grounded at the output jacks but not at the input jacks. Then they should also be grounded either through a metal chassis (for stuff with two prong plugs) or through the line source (for stuff with three prong plugs). If every thing is done that way, it ought to be essentially impossible to create a ground loop. Of course we do not live in a perfect world and a manufacturing defect could happen that leaves you with some improperly grounded item.

The only real way to figure that out is to go for the old fashioned troubleshooting approach and disconnect everything, then rebuild your setup until you find the culprit. When you do, you can have the device repaired or exchanged (if it is still under warranty) or you can use any of the various toys that are appropriate to isolate the offending component. $100.00 monster cables may make give you some fake prestige points but they do not fix the problem.

Another possibility is that your problem lies in your AC wiring. That could be either a monster to figure out or it could be an honest mistake on your part. Remember that lots of components may be grounded through your home wiring so it is certainly possible that they can interact that way as well.

Anyway, you have a huge TV and an amplifier and who knows what else that is drawing high current. Did you get close to or even go a bit over the 15 amps that most lines can carry? Did you solve that by plugging some components into different branch circuits? If you did that, then you may have made your very own ground loop through your service panel.

The best way to deal with that is to have a dedicated line brought up to run everything and make sure that it can carry plenty of amperage (I would even allow a bit of overhead for future expansion). If you can't have an electrician do that, then you may have to fall back to isolating components. However, you should be able to isolate just the surge protectors and not what is plugged into them. Remember that they have a bus topology and when you plug stuff into them you are building a star.

There are other possible screwups that can cause your ground loop and they can be frustrating as well but that should get you started towards finding the more obvious problems and finding a fix that is as inexpensive as possible.

So think like an engineer on this one and try to solve the problem. Be glad that this is a long weekend. Happy troubleshooting P--)

Didn't see there was a reply...
I let the corporate America dip into my wallet because I simply don't have the time. Also like I said the insurance company was taking care of it and paying for it. I figured that people who fix TV sets all day, every day for over 30 years would easily recognise the problem. (But they didn't after 4 tries...ugh) So fixing it myself should save the insurance company some money and help keep the rates low. I tried getting my money back on the digital boards they replaced needlessly...with no luck.

So I just got both the power plug "Hum X" ground loop eliminator and the Jensen Cable line isolator and plugged them in just like the internet articles said... So far I have not seen a single line of interference!! I have some more testing to do but I think this solved the problem completely! (I hooked them both up at once so I don't know if the problem was coming from the wall power or the cable TV line...but really I don't care now that its fixed.)

TommyHolly said:

and I bought the Jensen Cable TV Ground Loop Isolator from http://www.markertek.com/SearchProduct.asp?item=JEN-VRD1FF&off=0&sort=prod for $55

(I wanted to buy the same type of Video Hum Ground Loop Eliminator for the 3 RCA Component Video cables but that costs over $500!!! Yikes! So I'm just gonna get these 2 things and hope this works.)

Here are my questions:
1. Can I plug in the electrical Ground Loop Isolator into the wall socket and then split it? (Or more likely do I have to figure out what the exact devices are that are causing the hum and use that on each and every one of them?)
2. Are there any RCA component Video hum isolators out there under $500 because that price is insane.
3. I think the lighting rails in my house and especially in that room are the culprits. Is there any way to isolate them?

Click to expand...

I wish I had seen this thread earlier about your ground loop problem before you shelled out the $50 for the Jenson ground loop isolator. This is the same thing for $12.25 shipped. Same quality, same specs.

I had a similar problem as my damn cable outlet was fighting for the ground with my subwoofer, but the cable outlet is usually the root problem for this issue no matter the device affected in your home theater. That Holland $12.25 isolator fixed my problem. A friend has the Jenson $50 one and he tried mine and was ****ed off he spend $50 for the same thing. (If you did a forum search for Ground Loop you would have seen my post about this inexpensive $12.25 isolator)



EDIT: (added Cencoms phone number)

Tommy, if you have any further issues or questions, go to Cencom and/or give them a call, Phone: (801) 420-5245

They are VERY knowledgeable and have many many parts at really good prices and they ship fast. I believe all the listed prices are the shipped price. They are friendly people that know their stuff.

I did a search under Froogle, MySimon, and just plain Google looking for the best price on the Ground Loop Isolator. That company "Cencom" never came up on a single search. You should tell them that they are not being included on Shopping Bot searches because they are really missing out on business if thats the case.

TommyHolly said:

I did a search under Froogle, MySimon, and just plain Google looking for the best price on the Ground Loop Isolator. That company "Cencom" never came up on a single search. You should tell them that they are not being included on Shopping Bot searches because they are really missing out on business if thats the case.

Click to expand...

I'll do that, because they are a great outfit and that high quality Holland ground loop isolator for $12.25 shipped is the best price you will find anywhere on the net for the device. Cencom's staff will take the time on the phone to help diagnose and recommend a solution to any particular problem, plus they actually know what their talking about.

I meant to make a thread about how to rectify the ground loop problems many people are aggrevated and plagued with, but will do so after Thanksgiving as this is a common problem, most end up buying the Jenson thinking that's the best option.