Neotec NT-2702 problems interfacing with PC

[lee_stow]

I have a San Francisco Rush 2049 Special Edition cabinet with a Neotec NT-2702 monitor.  From what I can gather, this is a full VGA, 31.5khz monitor with a resolution of 640x480.  Ive ran into some issues with connecting to PC.  First, I had to attach a vga cable to the monitor.  The monitor has 5 wires - red-blue-green-black-white.  Black is ground and I'm pretty sure white is composite sync.  My vga cable has h-sync and v-sync.  I have tied those both into my composite sync on the monitor.  I connected the vga cable to the vga out port on my laptop.  Scrambled picture.  So, I changed the resolution to 640x480 60hz, with quickrez.  still all scrambled.  I did try and mess with the sync knobs to no avail.  So, I started trying different resolutions.  640x400 60hz worked!.  Only issue is, it has these white horizontal lines.  Can someone please point me in the right direction.  I'm a total noob with arcade monitors, but can do research.  I'm just stuck.  Attached is a picture of the screen.  The diagonal black lines are only present in the photo, so just ignore those.

Edit:  After finding another post on this forum, it looks like I just needed to adjust to contrast and brightness controls a bit.  I could still use some help on why I cant run this thing at 640x480 though, if anyone has any ideas.  Thanks in advance.

[buttersoft]

Assuming your monitor is 31kHz (because you say it is, but i don't know myself) it would be an issue with the modeline being sent and what the monitor is capable of.

For some general information on those two factors, take a look at the below links - remembering that different programs and OS's may represent modelines differently and use diferent etrms despite certain common factors.

Section e) of this guide (keeping in mind that it's for 15kHz, not 31kHz specifically) - https://www.aussiearcade.com/forum/arcade/m-a-m-e-emulation-projects-and-discussion/89704-a-guide-to-connecting-your-windows-pc-to-an-sd-crt-tv-pvm-or-arcade-monitor#post2194681

Also
https://arachnoid.com/modelines/
and probably
http://forum.arcadecontrols.com/index.php/topic,116023.0.html

Here is a typical modeline with the image size I needed for my panel (image size 1280x768, 60 Hz refresh rate):

Modeline "1280x768_60.00" 80.14 1280 1344 1480 1680 768 769 772 795 -HSync +Vsync
Here's a modeline with descriptive labels instead of numbers:

Modeline "String description" Dot-Clock HDisp HSyncStart HSyncEnd HTotal VDisp VSyncStart VSyncEnd VTotal [options].

Your monitor may have a very narrow scan range, or it may simply be that the PC is outputting sync in a way it does not expect, or a few other things. To play with your modelines, you can use a tool like CRU by ToastyX, or the Nvidia Control Panel, or, if you get really stuck, crt_emudriver. That last might need a bit of reading, but the support forum is the GroovyMAME subforum on here. You wouldn't be using the switchres functionality, just looking to setup some modelines.

The white lines are probably retrace lines, as you've noted.

[lee_stow]

Thank you very much for pointing me in the right direction.  I will research this a bit.