Konami to Jamma Adapter How to fix video problem?

Straker

Member
Joined
Oct 13, 2009
Messages
145
Reaction score
0
Location
Ludlow, Massachusetts
I have hooked all but the voltages but the -5v and 12. And the video RGB sync and ground. The monitor shows a picture that looks good overall but is bent on the far right side of the screen. I have tried this adapter with two different Konami boards and the picture has the same problem on both.

I am thinking that maybe it is the video ground as the Konami pinout does not show a video ground. So I connected the Jamma Video ground to one of the ground for power on the Konami pinout. The only other thing I can think of is either it really need the -5v or there is a sync problem. But I don't think the video would be stable if I had a sync problem.

Any ideas as to what the problem could be?
 
Thats strange.. I just took my Konami --->Jamma adapter out last night and put back the original Time Pilot board. I didn't have a problem converting to Jamma or back to the original game.. I've got a K4900 and a switcher installed.
 
I have hooked all but the voltages but the -5v and 12. And the video RGB sync and ground. The monitor shows a picture that looks good overall but is bent on the far right side of the screen. I have tried this adapter with two different Konami boards and the picture has the same problem on both.

I am thinking that maybe it is the video ground as the Konami pinout does not show a video ground. So I connected the Jamma Video ground to one of the ground for power on the Konami pinout. The only other thing I can think of is either it really need the -5v or there is a sync problem. But I don't think the video would be stable if I had a sync problem.

Any ideas as to what the problem could be?

I just go finished building an adapter to test my Konami (36 pin) boards in my JAMMA cabinet. I did the same as you, hooked the Video GND to the common GND. It's been working fine for me, granted I've only tested 1 board so far (Super Cobra) but minus graphical issues with the board itself, the picture looks fine. I recently bought another game that I'll be running in the cabinet (Rush 'n' Attack) and when it comes in, I'll hook it up and make sure that it has a good picture too... I'll report back either way.

Until then, try tweaking your monitor a little to see if you can get rid of that slope you have in your picture.
 
How about this: Tell us which monitor you have in it. It may be as simple as disconnecting (or connecting) the negative vertical sync pin.

Of course, this is assuming that your monitor has been capped in the not-too-distant past....
 
One other thing you may want to look at. If it is one of the adapters from jammaboards.com or similar, you may want to resolder the legs to the connector onto the pcb of the adapter. I had multiple issues with a couple I got, reflowed solder (and added a considerable amount as they really seem to skimp on it) and I haven't had an issue since.
 
Back
Top Bottom