Grounding indash touchscreen?

swift_gti · 08-29-2006, 06:12 PM

Hi all,

Nearly finished the carpc project now but i'm experiencing some interference through my amp - I've narrowed it down to the indash touchscreen, as soon as i disconnect the VGA and USB lead the whining stops.
How should I go about correcting the problem would I need to simply ground the touchscreen chassis or the actual USB and VGA connectors?

Cheers

Shadow · 08-29-2006, 08:48 PM

Have you disconnected the VGA and USB lines seperately? Do they cause noise when either is connected or do they both have to be connected?

swift_gti · 08-30-2006, 02:03 AM

From what I remember it done it which ever was still plugged in - so the touchscreen appears to be trying to ground through both of them.

Cheers

scott_fx · 08-30-2006, 02:11 AM

have you tried to more the ground to a better location? how is the screen powered?

swift_gti · 08-30-2006, 02:32 AM

At the moment the touchscreen is powered via the ISO connector where the headunit normally plugs in. Haven't tested another ground as of yet because I'm back at work today

Would grounding the chassis of the touchscreen do anything (as well as the normal GND cable on the ISO connector?
or would it need to relocate the GND on the connector block to somewhere on the body ?

Cheers

scott_fx · 08-30-2006, 03:30 AM

the chasis is most likely plastic, right? so that wont work. i would first try another ground piont. it doesn't have to be pretty for testing. just grab some wire and attatch it to the ground lead and test different spots. if the noise goes away then you know you have to dig into the tool box for some wire brushes or sand paper and get that baby a good ground. (a good test area to ground a wire to is the door catch or the main seatbelt bolt)

swift_gti · 08-30-2006, 08:30 AM

The chassis of the actual screen is metal (as its a din sized in dash one) but I will have a go at playing with the ground on the back first and see what happens.
Cheers

gt__1 · 08-30-2006, 08:47 AM

I had noise on my line as i am always redoing the system i didnt fix it right away. I had relocated some amps and rewired a bunch of things. I ran some cheap *** rca cables to my amp running my highs. So yesterday i grabed my good pair of RCA cables and the noise is now gone.

scott_fx · 08-30-2006, 10:10 AM

he already norrowed down where the problem is though. it's not induced noise from the rca's.

lostlurker · 08-30-2006, 11:21 AM

Scott_fx is right in checking diff ground locations. I would suggest just taking a decent ga. piece of wire and connect one end to your screens ground and the other to the same location where you grounded your amp. If the whine stops then route the wire under the carpet and such but don't waste time hiding wire until you find a loc that gives you the least whine.