ARpiCADE Forums

Hello ArPIcade! New customer here, but not new to the Raspberry Pi or arcade machines. My knowledge is not "expert" but at least what I would consider "somewhat intermediate." I love the product, but I'm have some questions on getting the display just right.

Here is my question and some backstory on the machine I'm using this on...


I have an original Donkey Kong machine that has been reverse converted to JAMMA. I have a JAMMA switcher in it with an ArcadeSD board in one slot and the Pi in the other.



The monitor is also original with the machine and it is in very good condition.


When I play on the ArcadeSD the colors look like the image above.


But on the Pi it looks like the above image.


Using the same Raspberry Pi & SD card image (the one that came with the arpicade) on a normal screen the colors at least look more like the original game.

Please help! What do I need to do to adjust? I know an answer is "adjust the monitor controls" but with the JAMMA switcher, I would have to keep adjusting every time I swap between the two boards. Is there anything in software on the arpicade that will allow me to fix the display?

Thank you in advance for your help!

Also, I should mention that I previously had a Game Elf plugged into the slot where the Pi currently is now, and if I put that back in, the colors are fine, so it's most certainly the Pi hardware that is giving me the trouble and I'm hoping there is a way to fix this. Thank you!

I'm really not sure whats going on there...

I'm guessing it's a Sanyo EZ monitor with the Nintendo inverter but as it's working fine with other game boards and the RaspberryJAMMA is working fine in other cabs I don't know what to suggest. On the DK cab it looks like the image is missing red with the RaspberryJAMMA, I'd check for a loose connection somewhere in the red signal path in the DK cab. As the Pi is putting out red on your other monitor maybe it's just an intermittant fault with the DK cab.

Hard to be certain, hopefully you can figure out what's happening. It may be worth trying to bypass the switcher board just to be sure too.

I'm guessing it's a Sanyo EZ monitor with the Nintendo inverter

Yes, that is exactly what the configuration is. Could there be a problem with the arpicade board? I tested both the Game Elf and the ArcadeSD in the same Jamma slot as the arpicade and they both look fine. And the Raspberry Pi plugged directly into an HDMI LCD screen looks fine. So if I rule those two things out, the only culprit would be the board that sits in between the Pi and the JAMMA slot.

Any other suggestions?

Thanks for the quick response! Really hoping I can get this to work!

Your HDMI to VGA converter may be faulty or not plugged into the Jamma Pi board properly.

I had the HDMI to VGA adapter on my original Arpicade board die last year, it would work about one in every 15 times the machine was turned on.

MadMungo wrote: ↑

Sat Mar 17, 2018 1:48 am

Your HDMI to VGA converter may be faulty or not plugged into the Jamma Pi board properly.

I had the HDMI to VGA adapter on my original Arpicade board die last year, it would work about one in every 15 times the machine was turned on.

I'm thinking maybe faulty? It's plugged in as tight as it will go, and I've even tried wiggling it around a bit and no change:

In a way I'm *hoping* that is my issue because that's easily fixable. I guess I should get in contact with the distributor next...

Is there a way you can connect your raspberry jamma directly to the machine without using all the other pcbs so you can rule the pcbs out?

mR_CaESaR wrote: ↑

Sat Mar 17, 2018 5:53 am

Is there a way you can connect your raspberry jamma directly to the machine without using all the other pcbs so you can rule the pcbs out?

When I first read this I thought to myself "why would I need to do that when the other boards worked just fine in those slots?" But then, I realized, you're right! As much of a problem solver that I am, ruling out any parameters seemed to make perfect sense. So I disconnected the JAMMA switcher and plugged the arpicade directly into the JAMMA connector:


Fired it up, and look what I see on my screen...

Well, HOT DAMN! It works!!!

But...that's weird. Why? I checked the JAMMA switcher and everything seemed to be in order. So why would it work outside of the JAMMA switcher but not plugged directly into it? Then I remembered what dee2er said a above...

it looks like the image is missing red with the RaspberryJAMMA

With that in mind, I went looking for why red would be missing. I plugged the arpicade back into the JAMMA switcher and inspected. Well, this is VERY interesting! Look what I found...


See that? The metal USB shield is touching the one of the RGB pins on the board...and it just happens to be RED! Well, crap. I have to assume that is the culprit here. Unfortunately, there isn't much I can do in this case because in both slots that metal USB part touches those pins! Thankfully, I remembered I had this laying around...


I grabbed my JAMMA extension cable, plugged in the arpicade through it, fired it up and LOOK!


Once again... IT WORKS!!!

So first of all, I'd just like to thank this community for helping problem solve this. In a weird way I sort of love when issues like this come up because they are "interesting" to me and I'm happy this one wasn't too difficult to figure out. Now I just need to find a better way to get those two metal bits not to touch. Perhaps just some electrical tape around both should do the trick!

In any case, I think I'm going to have a great time messing around with the arpicade board now as IMO it was the perfect solution for what I was looking for as a compliment to the Arcade SD board in my machine. The Game Elf was nice, but it just lacks so many features that I would have wanted (like high score saves, etc)

Once again, thank you for helping me figure this one out!

EDIT: Yep! A little bit of electrical tape on both metal parts and it works like a charm!

Glad you sorted it out. I will need to remember this for if I put my Arpicade into my other cab.
You could also just cut off the pin for the Red input, unless you're going to use the external input/s, but I don't think you ever will.

MadMungo wrote: ↑

Sun Mar 18, 2018 4:05 am

Glad you sorted it out. I will need to remember this for if I put my Arpicade into my other cab.
You could also just cut off the pin for the Red input, unless you're going to use the external input/s, but I don't think you ever will.

I did think about that as I probably would never use that pin, but I did think that if for any reason I ended up disassembling the JAMMA conversion and turning it back in to a DK cabinet (which can be done in about 5 minutes) and I wanted to sell those parts keeping them in great condition is probably best.

The electrical tape or the JAMMA extension cable seems to be a pretty good fix!