Ground loop issue

2010-11-22 16:22:24

#1

alexb: <3; +590|6197|Kentucky, USA

So, I get waves on any monitor that I plug in to my PC that move vertically at about 2hz (anywhere from very thin to almost half an inch wide). Turns out to be a ground loop issue - if I plug my monitor into a surge protector that has the third prong (ground) removed, and then plug that in into the same surge protector that the PC is on, the waves disappear. I'm pretty sure its the PSU because I tried it with two different monitors and cables and it still did it.

Could it be in fact the faulty PSU or maybe a faulty mobo? I don't have another PSU or mobo to test unfortunately, but I'm heavily leaning towards a faulty PSU.

Also, what is a good replacement PSU?

Last edited by alexb (2010-11-22 16:22:56)

2010-11-22 16:24:13

#2

Finray: Hup! Dos, Tres, Cuatro; +2,629|6045|Catherine Black

alexb wrote:
Also, what is a good replacement PSU?

Depends on how many igsaidwats you need.

2010-11-22 16:34:11

#3

alexb: <3; +590|6197|Kentucky, USA

Finray wrote:
alexb wrote:
Also, what is a good replacement PSU?
Depends on how many igsaidwats you need.

Phenom II X2 555 unlocked to X4 @ 3.2Ghz @ 1.35vcore
GTX 260 OC 650/1400/1000
4GB DDR3 RAM Dual Channel
4 Fans that have LED's
X-Fi XtremeMusic
1 Hard Drive
1 DVD/CD Combo Drive

2010-11-22 16:37:00

#4

Finray: Hup! Dos, Tres, Cuatro; +2,629|6045|Catherine Black

E: Nvm, I'd say this one.

Last edited by Finray (2010-11-22 16:37:45)

2010-11-22 16:43:28

#5

alexb: <3; +590|6197|Kentucky, USA

How about this one?

http://www.newegg.com/Product/Product.a … 6817139005

For about $10 more I'll get an extra 150Watts and 11 more amps on the 12v rail.

Last edited by alexb (2010-11-22 16:44:04)

2010-11-22 16:44:40

#6

Finray: Hup! Dos, Tres, Cuatro; +2,629|6045|Catherine Black

If you can spend the extra, sure it's worth it. I had that in my post before I edited

2010-11-22 16:45:49

#7

alexb: <3; +590|6197|Kentucky, USA

Finray wrote:
If you can spend the extra, sure it's worth it. I had that in my post before I edited

So do you think its the PSU and not the mobo? I didn't cheap out on the PSU... I bought this:

http://www.newegg.com/Product/Product.a … 6817341016

2010-11-22 16:46:49

#8

Finray: Hup! Dos, Tres, Cuatro; +2,629|6045|Catherine Black

Oh, I honestly have no idea about the problem, was just giving a recommendation on the PSU side of things. Sorry.

2010-11-22 16:55:03

#9

KEN-JENNINGS: I am all that is MOD!; +2,979|6889|949

Finray wrote:
If you can spend the extra, sure it's worth it. I had that in my post before I edited

no you didn't. maybe that was the one you were trying to link though?

I don't think it's the PSU. nvm, just read you swapped monitors...do you have another PSU you could swap/test?

2010-11-22 16:56:26

#10

alexb: <3; +590|6197|Kentucky, USA

KEN-JENNINGS wrote:
Finray wrote:
If you can spend the extra, sure it's worth it. I had that in my post before I edited
no you didn't. maybe that was the one you were trying to link though?

I don't think it's the PSU. nvm, just read you swapped monitors...do you have another PSU you could swap/test?

No, as I stated earlier, I don't have another PSU to try. Had I not sold my old rig, I could have.

2010-11-22 16:58:16

#11

alexb: <3; +590|6197|Kentucky, USA

I went ahead and ordered the CMPSU-650TX. If that doesn't fix the problem, the motherboard is next. I'll RMA this PSU once the new one arrives. If anyone can provide any feedback on this issue, that would still be appreciated.

Last edited by alexb (2010-11-22 16:58:51)

2010-11-23 00:36:05

#12

Freezer7Pro: I don't come here a lot anymore.; +1,447|6454|Winland

You most probably won't fix the issue that way. Grounding problems have nothing to do with the power supply in your computer. Have you tried changing power cable to the screen? Have you tried a different VGA/DVI cable?

The idea of any hi-fi system is to reproduce the source material as faithfully as possible, and to deliberately add distortion to everything you hear (due to amplifier deficiencies) because it sounds 'nice' is simply not high fidelity. If that is what you want to hear then there is no problem with that, but by adding so much additional material (by way of harmonics and intermodulation) you have a tailored sound system, not a hi-fi. - Rod Elliot, ESP

2010-11-23 06:37:57

#13

alexb: <3; +590|6197|Kentucky, USA

Freezer7Pro wrote:
You most probably won't fix the issue that way. Grounding problems have nothing to do with the power supply in your computer. Have you tried changing power cable to the screen? Have you tried a different VGA/DVI cable?

I've tried my older monitor with it's own set of cables, and I even tried using a DVI to VGA adapter on both monitors.
I really think it's a power issue because when I used an 8800, the waves were were less, and the 8800 uses one less 6 pin connection.

2010-11-23 06:51:46

#14

alexb: <3; +590|6197|Kentucky, USA

Also, the higher the FPS I'm getting, the more obvious the waves are. Using vsync lowers the amount of waves but they're still there.
The power supply makes an occasional buzzing sound (I think it may be some electrical interference though) and it also whines at certain menus of games (I'm not sure if it squeals but it does get really high pitched depending on what's on the screen). I think it is the power supply because isolating the monitor ground from the PC causes it to go away - every component in the PC is grounded to the PSU, and if it's not functioning, it would cause the waves I'm seeing, similar to a laptop when you unplug it's charger.

Last edited by alexb (2010-11-23 06:54:46)

2010-11-23 09:06:56

#15

Freezer7Pro: I don't come here a lot anymore.; +1,447|6454|Winland

Isolating the ground of the screen points toward a grounding issue, not a power supply issue. The ground inside of your case is the same as the ground in the grid. If it also flickers when using a DVI cable, it seems very unlikely for it to be related to anything inside of your computer.

To clarify -- does your screen flicker when nothing is moving on it? Does it flicker in movies too, or is it just when you're loading your GPU down?

The idea of any hi-fi system is to reproduce the source material as faithfully as possible, and to deliberately add distortion to everything you hear (due to amplifier deficiencies) because it sounds 'nice' is simply not high fidelity. If that is what you want to hear then there is no problem with that, but by adding so much additional material (by way of harmonics and intermodulation) you have a tailored sound system, not a hi-fi. - Rod Elliot, ESP

2010-11-23 09:10:26

#16

[HOF]Mercenary: o_O; +53|6436

I had the same issue, I used a 3 prong to 2 prong adapter (eliminating the monitors grounding) and the flickering went away.

2010-11-23 12:23:40

#17

alexb: <3; +590|6197|Kentucky, USA

Freezer7Pro wrote:
Isolating the ground of the screen points toward a grounding issue, not a power supply issue. The ground inside of your case is the same as the ground in the grid. If it also flickers when using a DVI cable, it seems very unlikely for it to be related to anything inside of your computer.

To clarify -- does your screen flicker when nothing is moving on it? Does it flicker in movies too, or is it just when you're loading your GPU down?

I've only noticed the flicker in video games; although it will do it whether there is little to no load (in menu's before the game is loaded), and also when there is load on the graphics card. I figured the power supply's ground isn't working or it isn't working well, because I did not have this issue with my older rig.

2010-11-23 13:38:43

#18

Freezer7Pro: I don't come here a lot anymore.; +1,447|6454|Winland

I asked whether or not you get noise without any load at all on your GPU, say, when playing a video in a media player, or just when you're looking at your desktop without anything moving about at all.

Does the noise look like fuzzy lines or a flicker over the whole screen, or is it in the shape of pixel-sharp lines running horizontally across it? If the latter, it's most likely a problem with your GPU in one way or another.

Do you get noise if you connect one of the inputs of your screen to the troublesome computer, and another to another computer, looking at the signal you get from the other machine?

The idea of any hi-fi system is to reproduce the source material as faithfully as possible, and to deliberately add distortion to everything you hear (due to amplifier deficiencies) because it sounds 'nice' is simply not high fidelity. If that is what you want to hear then there is no problem with that, but by adding so much additional material (by way of harmonics and intermodulation) you have a tailored sound system, not a hi-fi. - Rod Elliot, ESP

2010-11-23 17:09:14

#19

alexb: <3; +590|6197|Kentucky, USA

Freezer7Pro wrote:
I asked whether or not you get noise without any load at all on your GPU, say, when playing a video in a media player, or just when you're looking at your desktop without anything moving about at all.

Does the noise look like fuzzy lines or a flicker over the whole screen, or is it in the shape of pixel-sharp lines running horizontally across it? If the latter, it's most likely a problem with your GPU in one way or another.

Do you get noise if you connect one of the inputs of your screen to the troublesome computer, and another to another computer, looking at the signal you get from the other machine?

I only see the noise in video games - none in the desktop or videos. It doesn't look like fuzzy lines, or pixel-sharp lines at all. It's not the GPU, I already tried an 8800GT and it did the same thing, except to a much smaller extent.

I don't have another PC that I can test it on.

It looks almost exactly like this, except at about 2Hz, and the lines are evenly spaced out.

Last edited by alexb (2010-11-23 17:11:27)

2010-11-23 18:52:19

#20

alexb: <3; +590|6197|Kentucky, USA

I bought the GTX 260 off of max, I doubt he would shaft me. <3 max

2010-11-23 18:57:17

#21

unnamednewbie13: Moderator; +2,053|7029|PNW

Jumping into this thread cold, my suspicion would be a ground fault originating at the outlet or a faulty surge protector. You could try another outlet or surge protector, or both.

2010-11-23 19:13:25

#22

13urnzz: Banned; +5,830|6755

dirty, dirty power . . .

2010-11-23 19:17:51

#23

alexb: <3; +590|6197|Kentucky, USA

unnamednewbie13 wrote:
Jumping into this thread cold, my suspicion would be a ground fault originating at the outlet or a faulty surge protector. You could try another outlet or surge protector, or both.

I've already tried both, unfortunately it didn't fix it. I even bought a $55 Philips surge protector with "Pure Power Noise Filtration".

Last edited by alexb (2010-11-23 19:19:01)

2010-11-24 22:44:53

#24

unnamednewbie13: Moderator; +2,053|7029|PNW

But did you test for a ground fault on your outlet(s)?

2010-11-25 12:28:21

#25

alexb: <3; +590|6197|Kentucky, USA

unnamednewbie13 wrote:
But did you test for a ground fault on your outlet(s)?

I inspected the outlets and they seemed fine. On my old PC, I didn't experience this issue, so its safe to assume that the outlets are okay.

BF2S Forums Ground loop issue

alexb wrote:

Finray wrote:

alexb wrote:

Finray wrote:

Finray wrote:

KEN-JENNINGS wrote:

Finray wrote:

Freezer7Pro wrote:

Freezer7Pro wrote:

Freezer7Pro wrote:

unnamednewbie13 wrote:

unnamednewbie13 wrote:

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