lines in 2nd and 3rd screen (RCA connected)

**nemo1** · 06-02-2011, 03:15 AM

Hi... I am connecting 2 extra screens to my carpc. I took the vga output from motherboard and connected it to a vga to rca converter then a splitter to get 2 extra displays. The main display is onboard of motherboard. The 2 display from splitter works well when everything is inside house but when it is connected inside car, there are line in the display from the splitter. Anyone encounter this before? Any advice will be appreciated.

Thanks

**soundman98** · 06-02-2011, 08:07 PM

sounds like a ground loop. where are all the devices getting power from?

**nemo1** · 06-02-2011, 08:43 PM

I noticed one thing is that it only happens to the RCA screens and not the one connected onboard (motherboard). I tried a couple of options.

The power for the RCA screens was taken from:
1. I took the power straight from car battery.
2. From M2-ATX.
3. Desktop computer power supply from house mains with car PC powered by M2-ATX.

All of the above did not work. The screens flickers and after a while it even lost display for a couple of seconds and then back on. Could it have something to do with the splitter. There is an RCA video splitter after the VGA to RCA converter. The VGA to RCA converter has a 5v input voltage using USB from carPC.

Thank You for the reply.

**soundman98** · 06-02-2011, 08:56 PM

have you tried a single rca screen without the splitter?

**nemo1** · 06-02-2011, 10:30 PM

Tried powering the converter (USB 5v) and VGA from a laptop and the display is good on both screens.

**soundman98** · 06-02-2011, 10:35 PM

well, it really sounds like the video converter wants better filtered power then what the m2 can supply... if you are handy with electronics, you might be able to connect a capacitor to the power input in a attempt to filter some of the noise, but if not, and different video adapter might be a better option.

**nemo1** · 06-02-2011, 10:44 PM

I'd like to try the filter method (cap). What value should I use and is there any polarity when connecting the cap? I am assuming to connect it in parallel right?

**soundman98** · 06-02-2011, 11:04 PM

i would probably recommend starting with a 0.33uF tantalum capacitor-- i believe these are better at higher frequencies-- like those from the m2.

they do not have any polarity, and yes, you would connect it across the positive and negative terminals.

if that doesn't work, the next step would be to use a linear 5v regulator to separately power the video converter:
http://sharp-world.com/products/devi...pq05rd21_e.pdf

**nemo1** · 06-02-2011, 11:20 PM

Can I use any 5v regulator? If powering the converter seperately meaning I would take 5v from M2 to 5v regulator to converter?

Thank You for all the help.

**soundman98** · 06-03-2011, 05:02 PM

i specifically deal with the sharp regulator mentioned above, though i believe any other voltage regulator will work as well-- just be sure to use a heat sink.

as for the connections, you could connect it to the power input terminals of the m2, not the 5v wires.