Very very interesting problem (VERY WEIRD Carnetix issue)

**Urinemachine** · 07-31-2005, 09:37 PM

So I was driving around in my car w/ the carnetix powering my Lilliput and Epia system. All of a sudden i have BAD ground noise. Never had any ground noise before. I get home, can't figure it out so I just pull remote wire so nothing turns on and drive home. I get home and start pulling stuff apart, then i find the WEIRDEST THING happening.

Ok, the carnetix has a +12v out, a ground to PC, and two wires out to trigger motherboard to power on and shutdown. Well, I decide to pull wires while PC is running, so I turn car on / pc on (with horrible speaker noise) and pull the ground wire. I've done this before to kill the PC in case of a hang or something. However, the computer STAYED ON! So with 12v, two mobo wires connected, and NO GROUND WIRE, the damned thing was still running!!! Then I tried again with some USB from Lilli in and Monitor SVGA cable in too. I pulled monitor, I pulled ground, i pulled motherboard switch triggers, and left USB, and the computer was still running! Although it seemed like the hard drive powered off, the computer was still on. What the HECK is going on? Is my carnetix kaput and somehow providing ground over another wire?! I can't believe this and its freaking me out. Please help guys, got car shows coming up and need my system working!

Also, before anyone asks, the computer sits on MDF in a 3688 case and has no metal contact with chassis

**KyleYankan** · 07-31-2005, 09:48 PM

I know someone else here had a similair problem. turns out his system was grounded throw the shielding of the speaker out of the computer.

**Urinemachine** · 07-31-2005, 10:17 PM

Originally Posted by KyleYankan

I know someone else here had a similair problem. turns out his system was grounded throw the shielding of the speaker out of the computer.

I am using external USB audigy 2 NX

**KyleYankan** · 07-31-2005, 10:31 PM

Well, the ground of your PC is probably connected to the USB's shield, which in turn it probably connected to the audio's shield, which in turn is grunded to the amp, which is grounded. By makig that your ground, it's like hooking your altenrator up to the audio wires - you'll get GOBS AND GOBS of whine.

**yonu** · 07-31-2005, 11:23 PM

I had this same problem about a week ago when i was reinstalling my heaunit and forgot the ground turned out it was using the aux in as a ground

**KyleYankan** · 07-31-2005, 11:33 PM

i had the problem a few years ago installling my HU. the ground was the antenna shield

**Urinemachine** · 08-01-2005, 12:55 AM

Originally Posted by KyleYankan

i had the problem a few years ago installling my HU. the ground was the antenna shield

Thing is, this JUST happened. I never had an issue before until the other day. How do I go about fixing it?

**KyleYankan** · 08-01-2005, 01:00 AM

Have you tried checking your ground? The wire might have broken, or anythign along those lines. First thing is first: isolate your comptuer completely. Unplug all accesories, evverything you can. Then try reconnecting 12v, and ground. Maybe your ground rusted, or maybe the lead in the PSU broke.