Split video issue in JAMMA signal


I’m looking for some feedback on how to resolve this issue. I have a head-to-head setup between two Astro City machines and I’m splitting the JAMMA signal with this:

Sanwa CHS-TS2


The problem I’m seeing is the ‘slave’ machine’s monitor configured to be P2 is showing a very dark image regardless of the game hooked up. I’m not able to retest this right now, but I know that prior to the H2H setup, the P2 cab didn’t have this problem when it was running a game separately. The image was bright and colorful, exactly like what the P1 cab looks like now.

I’m also now splitting video from the P1 JAMMA harness prior to the CHS-TS2 connection into a 5v powered VGA-out video converter for video capture/third display and that video feed looks very clean, much like the P1 monitor. I don’t think this setup would be the issue, since I had the P2 dark image problem well before I split the video to the converter. However, what I’m wondering now is if I need some kind of amp or additional power sent to the P2 cab in order to boost the video image/performance. I’m no electronics expert by any means, but I can see that the video feed from the original P1 JAMMA harness seems to be fine, even when it’s split into the powered converter and the P1 monitor. The 5v feed is coming from the P1 JAMMA harness, btw.

Just so I’m clear on the setup, it looks something like this in outline form (sorry, no images currently available, maybe sometime over the weekend hopefully):

P1 JAMMA harness
VGA-out video converter
[INDENT=1]video signal spliced into the converter (then output to a VGA monitor) and into CHS-TS2[/INDENT]
Sanwa CHS-TS2

In case anyone asks, I already tried to play with the P2 monitor settings and nothing doing as far as brightening up the image to a satisfactory state. I’m pretty convinced it’s an issue somewhere within the CHS-TS2 wiring, but I’m not sure where and how to resolve it.

Hopefully I’m missing something obvious that you guys can identify for me. Let me know if any additional info is needed from my end. Thanks in advance for any assistance.


How do you have the video converter hooked into the jamma harness? I believe the issue is coming from there since depending on what you’re using it might need to be run in serial for it to work properly.


If it’s easy to do, what happens if you don’t plug in the P2 monitor?


My post was slightly modified to describe the VGA out conversion. Thanks for the feedback.

I spliced the wires for red, green, blue, v.sync, and ground into the converter, along with ground and +5v for the power. It is this part exactly, for reference.

Can you elaborate on the potential serial requirement? Did you run into anything like this on your setup initially?

I’m a big fan of Don’t Blow This, btw. It’s no accident that my setup is a lot like what you guys have. Definitely an inspiration.

It’s not a problem. All I would need to do would be to unhook the harness for the P2 cabinet. Anyway, I did that, hooked up a game straight to the P2 cab’s harness and the video looks perfect.

Like I said, nothing appears wrong with the P2 monitor and no issues when used as a standalone cab. I only started seeing this issue after splitting the video between P1 and P2, way before anything else went down.


Sorry, if the P2 is dark, can you try unhooking just the P1 monitor, but using the same harness, and are the P1 and P2 monitors the same make & model?


I’m not sure if this is possible, but I’ll try it out, hopefully tonight. As far as I know, they should both be the same model. It’s whatever that normally comes with an Astro City, so it’s that. The only difference I’ve noticed is that the P2 cab has controls for monitor settings in the control panel internal area, where the P1 monitor does not. I’m not sure if this means the monitors are the same or not.

I’m still thinking it’s something bad in the wiring, but yeah. Whatever you guys or anyone else can help me out with is great. The setup is already playable, now I’m just trying to make it as perfect as possible.



[INDENT=1]If you’re concerned about the wiring proper - that harness doesn’t look particularly complex. It should be pretty straightforward to check it with a multi-meter.[/INDENT]


Sure. I have a multimeter and can do that if necessary. I guess the information I’m really trying to get is what others have experienced using either the Sanwa CHS-TS2, a hacked D&D link cable (also curious as to why it needs to be hacked), or a custom link cable setup otherwise. I can’t imagine what I’m running into is a new problem. Tetsuosan mentioned something about a serial setup, so I get the feeling some kind of information is out there.


I’ve just started tinkering with these things. My current guess is that the P1 monitor has a lower resistance than the P2 monitor, and that’s causing the P2 monitor to be darker, but there’s a whole slew of other, more subtle possibilities.