HELP: CarPC produces horizontal lines on Acura TL stock screen

**GIVER** · 10-10-2007, 03:31 PM

Hi, I desperately need the help of the mp3Car forums.

I have a CarPC installed in my 2006 Acura TL. The video output from the PC is currently a S-video output, connected to an S-video to composite video cable, which is connected to a TV&Nav switch module. The output from that module is connected to the TL's stock screen. This configuration has so far produced the best results, as I've tried the following configuration; PC output VGA, connected to a scan converter (AverMedia iMicro), which is then connected to the TV&Nav module via composite or S-video output.

The problem:
The output on my Navigation screen is showing horizontal lines. I've recorded a little video with my cell phone to give you an idea of what lines I'm talking about.

Video: HERE

These lines are constant and very annoying. I need to keep the stock TL navigation screen because I don't want to lose the navigation system capabilities, that's why the video has to go through the TV&Nav module. It acts as a video relay between the PC and Navigation System to the stock screen.

My theory is that this has something to do with the refresh rate at which the PC is outputting the video signal. The problem is that the PC has an Intel 945GM graphics processor, which isn't very flexible regarding refresh rates and resolutions.

Here are just some of the things I've already tried:
- Adjusting various resolutions. For best results so far I use either 720x400 resolutions or 800x600. Neither of which are perfect, but closest I could get to what I need.
- Adjusting refresh rate (only options are 50Hz or 60Hz)
- Tried using PowerStrip software to create a custom resolution and refresh rate, however, PowerStrip doesn't provide good support for Intel based graphics cards and doesn't allow me to modify the refresh rate or create a custom resolution.
- Tried connecting the video signal from the PC to a standard home tube TV. Video does not flicker or produce lines.
- Tried connecting a car DVD player to the TV&Nav module instead of the CarPC and video quality is excellent.

I've tried many options and am still looking into it but I'd like to know if anyone else has any good suggestions.

Here are some things I have recently come up with but haven't tried yet:
- Connect a laptop with an Nvidia graphics card to the TV&Nav module via S-video cable and S-video-to-composition adapter.
- Try installing Intel's Embedded Graphics Drivers to see if I can get some more flexibilty from the Intel 945GM graphics processor.
- Acquire an Nvidia desktop graphics card and insert it into the CarPC, then try using PowerStrip to create a custom resolution and refresh rate.

I really hope there's some car video expert or a computer guru out there that can provide me with some guidance or advice. Please let me know if I forgot to mention something. Thanks in advance.

**nst6563** · 10-11-2007, 03:05 PM

Definately looks like a refresh rate issue. In the display properties under the monitor tab, have you unchecked the box that says "hide modes this monitor cannot display"? Usually unchecking that reveals some more options.

From the way it rolls though, looks like it's a few hertz off. Don't think it's running at a 59hz frequency do you? Or interlaced maybe?

Just curious though...have you tried to see if it might be caused by grounding or interference? I had lines similar to that on my 7" lilliput (they didn't roll like that though) that I resolved by grounding.

**GIVER** · 10-11-2007, 04:38 PM

I will check the ground this weekend to make sure it's not causing the interference. The reason I didn't think grounding was an issue before was because when I hooked up a standard car DVd player to the TV&Nav module, the picture quality was near perfect. In order to get to the TV&Nav module now I'd have to rip open the trunk again. I'll try to do that this weekend.

**nst6563** · 10-11-2007, 05:51 PM

I went a little nuts on the grounding with mine. I grounded the motherboard, case, vga cable, and screen. If it's a ground issue, it may be caused by the motherboard/psu and not the TV/Nav module you've mentioned.

Dunno...tough one. I'd definately exhaust all the software options you can find first if it involves dis-mantling things.