Ground Noise: Tried everything nothing work

**smhussain** · 01-01-2009, 09:03 AM

I have the following computer:

1. M2-atx psu
2. Intel d945gclf2 mobo
3. Hard drive

I own an rx8 and installed my carpc is center pass through(please see attachment for pictures). The passthrough is made of plastic.

After completing my install i experiences serious noise from all speakers. The noise increases as the engine rpm increase. I read some threads and thought it was a grounding issue. So i installed metal plates under both mobo and psu and grounded these plates via a wire to my car body.

Installing metal plates took me five hours and still the noise persists. Somebody help me or someone around me is going to get seriously hurt...arrgggggggggghhhhhhhhhhhhh.

**Minoritydan** · 01-01-2009, 10:24 AM

Did you install a GLI?

http://www.radioshack.com/product/in...ductId=2062214

**Machinehead** · 01-01-2009, 10:32 AM

A couple of options to try:

1) Try grounding your equipment to a different point, it needs to be bare metal that's attached to the vehicle's frame. Those metal plates need to go to ground as well.
2) Ground loop isolator. $16.99 at radio shack.
3) Try using a higher end shielded audio cable and route it away from any power sources. Don't skimp here, a $5 cable isn't going to cut it.
4) External sound card. Don't go cheap if you have to go in this direction. You get what you pay for.

**Woofnstuff** · 01-01-2009, 05:09 PM

dont run video and audio cables together,

do you have an amp?

**smhussain** · 01-02-2009, 05:07 AM

UPDATE:

1. I tried grounding everything that is mobo and psu at different places on my chasis but nothing helped. The strange thing is that in the process i accidentally ran my computer without a wire attached to m2-atx psu and the computer was working okay? How can psu run without grounding this is really strange for me.

2. I connected my speakers with my ipod and there was no distortion.

3. I connected my mobo with a headphones and again there was no distortion.

I will try to find a good ground loop isolator here and see where things go from there.

**HiJackZX1** · 01-02-2009, 06:12 AM

Sorry to cut in, but what happens if you install a GLI, and you still got a engine noise? I recently upgraded everything on my setup. I went from 5.1 to 7.1 so I have an extra pair of speakers in the back. One of the middle speakers though has a engine wine. Its the only one with it. I thought maybe the GLI kicked the bucket, so I changed it, still the same result. What on earth can defeat a GLI?!?!?!

**dirtylarry** · 01-02-2009, 07:02 AM

Originally Posted by HiJackZX1

What on earth can defeat a GLI?!?!?!

an italian plumber jumping on it while eating mushrooms.

**daveczrn** · 01-02-2009, 09:12 AM

Originally Posted by smhussain

UPDATE:

1. I tried grounding everything that is mobo and psu at different places on my chasis but nothing helped. The strange thing is that in the process i accidentally ran my computer without a wire attached to m2-atx psu and the computer was working okay? How can psu run without grounding this is really strange for me.

2. I connected my speakers with my ipod and there was no distortion.

3. I connected my mobo with a headphones and again there was no distortion.

I will try to find a good ground loop isolator here and see where things go from there.

1) my guess would be that it's using the ground from the motherboard to ground itself. That's why it worked. I would not do this for long as i doubt the motherboard has a large enough ground to sustain the power supply for long.

2.3) Just because when you hooked up your ipod it doesn't mean that the ground isn't coming from the amp. Or that the mobo isn't doing it either. It just means that the way you connected the speakers and ipod didn't alow the ground noise to go through the system. It does sound like the ground loop isolator will do the trick though.

edit... I found a picture to explain how a ground loop works kinda... all you need to do is disconnect the loop.

**HiJackZX1** · 01-02-2009, 09:44 AM

Here is maybe your issue. This is what is mine also, and driving a car with a high output alternator doesnt help me either. I have to assume you made your own ground point for the PC? My PC is in the middle of the car, and because the ground has to be as short as possiable (under 3 feet), I couldnt connect to an exsisting ground point, I had to make one. Because the PC is not on the same ground point as the car radio wiring, and what not, it creates a ground loop. You can take apart, rearrange and what not, you install trying to get rid of the ground loop, but in the end, because it isnt on the cars main ground, you will always have the ground loop.

**PaulF** · 01-02-2009, 12:58 PM

The computer was able to power up without the ground being connected to the ground on the PSU because the PSU has a grounded case which probably came in contact with those metal plates some how.

In my car install, the culprit of my buzzing was that my RCA audio cables were run next to an extension cord run from an inverter. If you have an inverter anywhere in your car, try shutting it off.

I haven't put a computer in my car yet, but I'm a computer hobbyist and a lot of times a sound card that is integrated onto the motherboard will have noise from the other devices on the board. Try an external sound card or at least PCI sound card I've never seen one of these that puts out noise. Although I highly doubt this is the problem since you said there was no distortion on your headphones.

Where is the computer located in your car? Try hooking up the Ipod right to the audio cable that is normally connected to the computer.