Ok, I am at my wits end. I went to great lengths to set up media room in my basement. I have a plasma in my living room, master bedroom and office all of which are controlled via Control4 and cable boxs in my basement. When I got everything set up, I noticed a scrolling green bar and a faint redish pink bar. they are there on every channel. I have cox HD DVRs and ran component video over cat5 to each room. One of my instal techs recommended that I use specialty shielded cat5 when running video over cat5 and we thought for sure this was the issue. Well, I paid him to run super high quality HD RG6 and it was still there! So, I started troubleshooting for a ground loop. When I unplugged everything and tried different plugs in my basement, I noticed that when I changed the power outlet to a different outlet, the bars were dramatically reduced (but still there). I am using a Monster Cable Power surge center (3500 MKII). I have no idea what to try next. Is this a pure shielding issue? Is this a ground issue? what about my cable splitters and amplifiers? has anyone had this problem?

Definitely sounds like a ground loop.

The Monster Power bar isn't going help that. You need to break the loop(s).

I am a novice when it comes to electrical outside of audio equipment. anyone have some ideas on how do fix or trouble shoot this?

Here's a very good link to start with.

http://www.extron.com/technology/archive.asp?id=ts012002

Do you have a cable distribution amplifier anywhere in your signal path? If you do, the ground loop may be injected into the signal there. If so, breaking ground on any or all of your other components won't help, because the interference is already in the signal itself by the time it gets to your components. Even the cable grounding block (often outside the home) can become a ground loop source.

I had such a situation and spent a lot of time and some money with various schemes. What finally helped was running a 12ga wire from the grounding post of the cable amplifier (NOT the third pin on the AC plug!!) all the way back to the main grounding strap of my home's service box. This is on the main cold water inlet pipe before the water meter. The proverbial "single point of ground" was the key in this case.

Cinema Source: where I found my answer (http://www.cinemasource.com/articles/gnd_loop.pdf)

Audioholics: Eliminating Ground Loops (http://www.audioholics.com/tweaks/connecting-your-system/ground-loops-eliminating-system-hum-and-buzz/)

N.C. timestamp 9:21:06 AM

Do you have a cable distribution amplifier anywhere in your signal path? If you do, the ground loop may be injected into the signal there. If so, breaking ground on any or all of your other components won't help, because the interference is already in the signal itself by the time it gets to your components. Even the cable grounding block (often outside the home) can become a ground loop source.

I had such a situation and spent a lot of time and some money with various schemes. What finally helped was running a 12ga wire from the grounding post of the cable amplifier (NOT the third pin on the AC plug!!) all the way back to the main grounding strap of my home's service box. This is on the main cold water inlet pipe before the water meter. The proverbial "single point of ground" was the key in this case.

Cinema Source: where I found my answer (http://www.cinemasource.com/articles/gnd_loop.pdf)

Audioholics: Eliminating Ground Loops (http://www.audioholics.com/tweaks/connecting-your-system/ground-loops-eliminating-system-hum-and-buzz/)


Thanks. Yes, I do have 2 amps in my system. Was your situation only when you watched cable or on every video source? mine is on all video sources and I am assuming this can happen on a ground loop.

You might wish to check that all of the components in the system are connected to power outlests wired on the same phase of the fusebox. If you have components which are using circuit breakers on both sides of the box you will have created a ground loop. Correcting the problem may be as simple as changing the breaker which an outlet is connected on to the same phase to eliminate the scrolling bars in your display.

FIXED !!!!
(sort of)

OK, so I had my electricial friendout the other day and also cox cable. there was a ground wire not hooked up at the cable box but this did not fix it. we trouble shooted all cable issues and nothing worked. we thought it was my in way RGB cablerunto my tvs that may be getting electrical interference.


The electrician felt that it was a bad ground and we did find several ground cables not hooked up un several key places. We even had a ground and neutral hooked up to same place! anyway, this made a huge difference but it was till there slightly so we knew there were more ground issues somewhere in the series. So, we decided to unhook the ground in the A/C plug where the TVs are plugged into and VIOLA!!! its gone. Now my question is.....am I at risk of any sort of hurting my TVs?

Did you check to see if all of your system components are running on the same phase of the fuse box? If not this is likely the cause of the problem.

Do you have any dimmer switches for lighting near your system?
That is what my problem was. Cheap dimmers! Easy solution. It took me awhile to figure out what the problem was. My dimmers are on separate fuses and it still affects my projector! Maybe this will help.