# Noise from my monitors...



## stevemazzaro (Jan 7, 2011)

Ok, I unplugged everything and went straight from the PC to the monitors - the static was still there.

*edit* another thing I just noticed is that sometimes scrolling up and down with my mouse can cause it, as well. And if I unplug the rcas from the i7 machine (but leave in another rca into the behringer unit), scrolling the mouse still gives the static.


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## Nick Batzdorf (Jan 7, 2011)

I can't follow this, but is it airborne noise from the computer getting into your mixer?


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## rgames (Jan 8, 2011)

Not sure I completely follow, either, but it sounds like you have some type of power issue.

Is everything connected to a single power strip and on a common ground? Sometimes having different grounds can cause weird behavior like this (notebooks have this issue sometimes). Sometimes a single wall receptacle will have different grounds (e.g. if one of the outlets is controlled by a switch) so I'd start by making sure all power is coming from a single power strip - chain power strips if necessary.

Another thing you can try is removing the video card and powering up the PC. It won't boot, of course, but the audio card will power up and you can see if the noise is still there. The fact that mouse scrolling causes the noise hints that it might have something to do with the video card - if some chip on the card is dying it might cause issues with the power to the rest of the system, which will, of course, feed back through the power to the monitors.

Also might be the power supply, itself: do you have another power supply that you can try? Is your power supply rated high enough for the PC? If you have one of those mongo video cards and a bunch of hard drives you might be stressing the power supply - that could also juice the power line.

Yet another thing you can try is a UPS and/or a power conditioner - you might have really crappy power coming out of the wall.

rgames


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## williamrice (Jan 8, 2011)

My (long dead) sony vaio laptop used to do exactly this... it was really annoying!

You gotta assume that if the noise correlates to mouse/ video activity that it must be linked in some way to either the GFX card(s) / Displays + their PSUs / the USB buss.

I assume the noise stops when the new i7 machine is shut down?

Maybe it's some kind of ground loop picking up magnetic noise from either the new PC's PSU or the displays' PSU(s)?


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## stevemazzaro (Jan 8, 2011)

Thanks for the posts.

As far as power goes, I have my 2 monitors, my computer monitor, and the behringer unit plugged into a power strip into the top jack of the wall. I have my computers (and other random things) plugged into a separate power strip into the bottom jack of the wall.

I actually had video card problems and JUST replaced the card yesterday, but it did this before I replaced it, too.

I have balanced cables for my monitors (1/4" cords). The monitors are are about a feet each from my monitor.

And yes, the noise stops when the machine is shut down. It may be the power supply, but I don't have another one to test. 

I will try buying another PSU to try to see if that fixes anything.


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## Stephen Baysted (Jan 8, 2011)

If you turn your screen off - does the noise disappear too?


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## stevemazzaro (Jan 8, 2011)

It does not.


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## rgames (Jan 8, 2011)

stevemazzaro @ Sat Jan 08 said:


> As far as power goes, I have my 2 monitors, my computer monitor, and the behringer unit plugged into a power strip into the top jack of the wall. I have my computers (and other random things) plugged into a separate power strip into the bottom jack of the wall.


There's still a slim chance they're on different grounds even though they're coming out of the same receptacle. Also, one of the outlets might have a dodgy connection that's causing some issues - try chaining the power strips off a single outlet. Long shot but an easy check...



> I actually had video card problems and JUST replaced the card yesterday, but it did this before I replaced it, too.


OK - starting to sound like this is the source of your problems. Unfortunately, the fact that the problem remains hints that it might actually be on the motherboard or in the PSU. When a card dies, it can take part of the motherboard or power supply with it, so that might be what happened. Or, if you have a dodgy power supply or motherboard, it can cause issues with the video card. So if your new video card starts misbehaving, odds are the issue is in the PSU or the motherboard.



> I have balanced cables for my monitors (1/4" cords). The monitors are are about a feet each from my monitor.


The issue is that you're using unbalanced RCA out of the M-Audio card. Balanced cables might help but the underlying issue is still there. AFAIK, that card doesn't have balanced outputs. Plus I don't think it's your issue because you said there's no noise on the headphone output. If the noise were coming from the unbalanced connection, it would (probably) show up in the headphone output, as well.

rgames


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## JohnG (Jan 8, 2011)

I doubt this will help but it's a very inexpensive test.

Try "lifting"one, the other, and both your power sources, using a 3-2 prong power converter, but don't actually ground the little loop.

If it's a power thing this can help.

You also can get a power conditioner, like the Monster ones, but those are somewhat pricey. I have rotten power so I need them here.


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## stevemazzaro (Jan 8, 2011)

Just a little update. I bought a new PSU, same thing. 

I did what JohnG said, actually. Amazingly, it seemed to have fixed the problem. Still not sure why all of a sudden a grounding adapter was needed, but I'd like to thank everyone for helping me out with this. It is GREATLY appreciated.


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## careyford (Jan 9, 2011)

I'd try a simple "ground lift". Get one at the hardware store for a buck or two. Try plugging the mixer into it, then the monitors one at a time. 

Richard


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## JohnG (Jan 9, 2011)

I think that's what he's doing. That's what I was suggesting, Richard F. Richard A is concerned about safety of this approach.


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## rgames (Jan 9, 2011)

Things that pull a lot of current have a ground for a number of reasons. One is to keep the base voltage on the components (hence, ground) at the same level. If those levels are different, you're going to build up charge (static electricity) or generate currents (ground loops) that shouldn't be there.

If something fails and shorts to ground, it'll dump current through that path to the ground. If the intended ground is removed (as with a lifter), the one that remains likely is not designed to carry much current, so there's a good chance it will get very hot and might start a fire. If you get a charge buildup, it'll probably be on the case, so a person might get shocked when he touches it. It probably wouldn't be a harmful shock, but could be.

It's against every electrical safety regulation to bypass ground connections. The purpose of the lifter is not to remove the ground but to allow you to connect it somewhere else.

So it seems the underlying problem is with his ground connection. Either he has multiple grounds or there's a dodgy connection in the one he's using.

The ground line is partly a safety feature. Sure, you can bypass it, but it's better to just fix it.

rgames


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## stevemazzaro (Jan 9, 2011)

What do you suggest, rgames?


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## Stevie (Jan 19, 2011)

I'm pretty certain this is caused by the GFX card. Maybe your sound card is too close to the GFX card. I must confess, that I have the same issue, although my sound card is way down. But maybe you (and me) can try to put the sound card in a different slot.


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## Nick Batzdorf (Jan 19, 2011)

No, if you can lift the ground and get rid of it then it's a ground loop, not airborne.

Steve, try plugging everything into the same power strip and see whether that gets rid of it. Ground loop hum is caused by multiple paths to ground.


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## rgames (Jan 19, 2011)

It could still be related to the video card but odds are extremely slim it's an RF problem.

Steve - I assumed you tried running everything off a single power strip - did you try that? If that doesn't work, try running an extension cord (with a ground, of course) from another outlet and running the single power strip from that. There might be a bad ground in the outlet you've been using (which could have caused the dead video card).

If that doesn't work, try running everything off a UPS that includes some power conditioning. You might have really crappy power lines.

If that doesn't work, then there's a chance that your dead video card did, in fact, do some type of permanent damage to some other component when it died. Or, there might be a problem with a component on you motherboard that caused the video card failure and still remains (in which case your other card is sure to fail in short order  ). You might have a scenario where the computer can't handle being properly grounded because of some damage to some circuit that involves the video card. Again, if you boot without the video card you can get some insight there. It's not a certain indicator if the noise remains, but if the noise goes away, well, there you go.

If everything is properly grounded to a common ground, and your outlet has a good ground connection, and you have decent quality power, then I'm afraid the problem is likely in your computer.

rgames


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