Wells Gardner 19K4914 wiring help

[Love Rhino]

Hello everyone!  First of all, let me say that this forum has been a Godsend!  I am working on my very first arcade project: converting a Gauntlet cabinet to a MAME machine.  I am so very very new and green to things, and this site has been very helpful with design of the control panel which components to get.  I have made a TON of mistakes so far, but thats learning!

Currently I am working on connecting the monitor Wells Gardner 19K4914 to an arcade vga breakout cable I got from Ultimarc.  The monitor seems to have 5 wires currently going from the monitor into the existing circuit board: rgb, ground, and a white wire from negative h and v sync.  The arcade vga breakout cable has slots for the first four, but I'm not sure where to wire the white.  It is labeled for h-sync and v-sync, but what if you only have a wire for both?  Which takes priority?

I hope this question was asked with enough information, and I apologize in advance for being a noob!  Thank you all for any help!

[buttersoft]

If the original wiring had only those 5 wires, and the single white wire was going into "-ve H sync and -ve V-sync" as a single terminal, not split, then that's the terminal for Composite sync. If the chassis has no other spots for sync, no separate H- and V-sync terminals, whether positive or negative, and no switches to adjust this, then you have no option but to use Composite sync into that one terminal.

Assuming you're using a Windows PC source here, you can get composite sync from an ArcadeVGA or better yet an AMD Radeon card of the right sort using crt_emudriver. It will be output over pin 13 of the DB15/VGA plug, the same one as would carry H-sync under normal circumstances.

You can also look at combining sync for yourself.

I'm not sure if it's teaching your grandmother to suck eggs, but be aware that most PC sources need a video amplifier when connecting to an arcade monitor or the picture won't be bright enough, though IDK about Wells Gardener monitors in particular. A J-Pac is a good choice for this. It's not the cheapest option but it also lets you hook into the existing jamma setup so you don't have to rewire the cab's existing controls.

Happy to clarify anything, if you need.