NOISE help with laptop setup

**ccblanket** · 06-29-2005, 08:42 PM

not dead (yet)

.

what is a 4wd battery?

**sivart321** · 06-30-2005, 09:30 PM

I have the same problem. I can say for a fact that noise filters and ground loop isolators on the RCA's will not always help in this case. I also get noise through the VGA cable, using high quality VGA coax cables with ferrites on both ends.

I have almost given up, attributing it to the simple nature of these cheap switching DC-DC power supplies.

One option, if the correct voltage is available for you, is to use the carnetix power supply to power the laptop.

I have stopped worrying because I have decided to go to a micro atx/opus solution. The laptop had so many other problems that it is not worth the hassle.

Goodluck!

**pancit175** · 06-30-2005, 09:39 PM

Originally Posted by kuo

i'm running a laptop setup and i'm almost completely done except for this noise issue. i am using a dc-dc cigarette adapter for laptops for power.

The cigarette lighter is always the noisiest place for power. try running a new ground for the cigarette plug or just run power straight from the battery.

**krasniak** · 07-12-2005, 05:13 AM

i have the same dc-dc adapter and i've conected it (adapter & lcd TC) to new wires grounded in other place - nothieng happened; problem wosn't solwed

what shoud I do GLI ?? or what) PS Nobody in my poor cantry don't wont to help me, they say that there can be toomany posibilitis and too many work to find the problem. But i know the dc - dc adapter makes all the mass.

**jaripetteri** · 12-02-2005, 06:49 AM

I have also the very same problem with the same power supply. Have you measured the "grounds" electric potential between power supplys input and output grounds?

I'm just wondering if the power supplys input and output grounds are not connected together that could explain why there is the ground loop on signal line. I'll check that tomorrow and hope I do not blow up my setup totally...

I also get that engine rpm relaited noise when the charger is not connected on laptop but its a bit lower. When unpluged the laptop ground is not connected on cars ground anyway so grounding could be the problem there also, right? I have extra regulators for 12V and 5V's and those are already grounded on cars ground.

At theory the shouldn't be any problem if I connect laptops charger ground on cars ground, right?!? I need to do some studing there anyway...

**VitalRyan** · 01-15-2006, 07:25 PM

Pretty easy to fix actually...

First, answer this question, unplug your audio cable that runs from your laptop to your headunit/amps..... does the crackling go away?

If it goes away, simply buy a GROUND LOOP ISOLATOR off ebay for $10 shipped and that will fix it instantly... very simple.

If it does NOT go away, try powering your laptop from the battery instead of the cigarette lighter, chances are theres too much current and interference too close to your headunit from the cigarette lighter..... ground it anywhere, and get your power from the battery.

You can also easily test if this will fix it by attaching 2 long cables from your battery and attaching those to your power adapter before cutting it. Make sure you know which is negative and positive.

once you power it this way, if you still have whine, then try removing your audio cable again, if whine is gone, you now have a ground loop.. .get an isolator to fix that.

I would say i'm 98% sure this will fix your issue, there's really no other way you are getting interference.

**jaripetteri** · 01-16-2006, 01:24 AM

My problem was solved. I was changing regulator boars and find out that I have one bad ground contact there. Fixing that fixed 90% of noise and I think is fine now. Thanks anyway.