MiSTer FPGA Forum

I have a couple of problems but the one that is bugging me the most is when ever I connect my MiSTer to my arcade cabinet using Antonio Villena's Jamma addon I always get a green tint. If I remove the VGA cable from the IO board the green tint goes away. So I think it's the IO board not the Jamma addon. I even get the green tint if I connect the VGA to the Mister when it has no power. I have tried the SOG switch. No luck I've been at this for days and it's driving me crazy.

I also get terrible audio from the IO board which connects to the Jamma addon using the 3.5mm.

Depending on what you mean by "terrible" The DAC on the I/O board is known to be pretty weak/noisy. Using it as a mini-TOSlink for digital audio is recommended. No idea how that relates to JAMMA though, if you need analog audio you will get must better results using even a cheap external DAC.

Cabinet turned on with Jamma addon connected but no VGA connect to IO board yet everything looks normal

VGA connected to IO board but MiSTer not yet switched on and already has green tint.

Powered on and Streets Of Rage 2 running. You can see how the green tint is altering many of the colours


Moving the SOG just makes the Green tint even worse as you can see.


I hope this makes my problem more clear.

Do you have a picture of the output with the JAMMA adapter disconnected?

Also, Antonio has an email and does customer support. Go to his website to get his email so you can reach out to him.

I'm experiences exactly this issue, but I also have some lines at the top of my display.

I shot Antonio an email. Hope I hear back soon.

Did you find a solution for this, @Arcade Andy?


Edit:

Just adding two shots of my "green tint" issue.

aberu wrote: ↑Tue Mar 23, 2021 8:33 pm Do you have a picture of the output with the JAMMA adapter disconnected?

Also, Antonio has an email and does customer support. Go to his website to get his email so you can reach out to him.

Here's a pic of mine with the adapter disconnected from the IO board.
The lines are probably coming from the MiSTer itself or the interaction of the IO board with the JAMMA adapter.

My guess is something wrong with the cable or connector you are using for video, or something not totally compatible. The first route I would take is messing with the video cable you are using, personally. Even wiggling it a bit to see if it changes the green on the screen, especially since you have green lines.

aberu wrote: ↑Thu Mar 25, 2021 7:46 pm My guess is something wrong with the cable or connector you are using for video, or something not totally compatible. The first route I would take is messing with the video cable you are using, personally. Even wiggling it a bit to see if it changes the green on the screen, especially since you have green lines.

Actually I'm not using a cable, just connecting the adapter directly to the Mister's VGA. The VGA is outputting fine to other monitors I have as well.

I've also connected and re-connected a number of time with the same result. Strange.

I find the lack of documentation on this adapter mildly bemusing.

chanunnaki wrote: ↑Thu Mar 25, 2021 7:52 pm I find the lack of documentation on this adapter mildly bemusing.

Not super surprising given my experience with a product I've gotten from him before (I had to find a reddit comment of his after much googling for something that should have just been on his website).

I'm a little bit annoyed about this whole thing to be honest.

Nowhere on the site does it state that the adapter isn't immediately compatible with the official MiSTer. The least that could have been done was the include a gender changer for the price. From a technical and design perspective, it's pretty good, if used with their unofficial "MiSTer", but from a business point of view, it's an absolute shambles.

Connecting this JAMMA adapter directly to the MiSTer also renders the audio-out port inaccessible, so getting a gender-changer is absolutely essential to have autdio, but I don't even know if it's worthwhile getting the gender changer now cos I don't even know if anything will help me get rid of the lines or the green tint.

I'd guesstimate that the number of official MiSTer vs. this unofficial one numbers 1000:1 so it would seem to make little financial sense to hobble a product like this.

Oh well, caveat emptor I guess. I'm going to be far more careful what I purchase from now on and stick only to the addon's supported by the official respository.


Here the thing though... I was considering purchasing an unofficial MiSTer from said website as my second MiSTer, but after this, it's soured me on that thought completely.

Still haven't heard a peep from vendor. Losing hope. It's not even heavy enough to make a decent paper weight or door stop.

Just a random thought (which should not make a difference, but just in case)

have you made sure that you are not supplying VGA power at all. (there are jumpers on my IO board to select 3.3v or 5v if needed)

I fixed it. Using advice from Nat at https://misterfpga.co.uk.
Here is what he told me

"I've heard of similar issues with JAMMA type adapters, one solution I know which has worked in the past is remove C6 on the underside of the IO board it's the 100uf on the SOG switch, and just jumper it with a wire."

This is how it looks after jumpering C6.

Looks much better, good to see this worked for you.

Sorry to resurrect this old thread, but I'm having the same issue with a single core (the Sega 32x core). I would like to try to see if jumpering C6 on the underside of the I/O Board would rectify the issue.

I don't have much experience with circuit board wiring, so I'm just wondering if I'm supposed to solder a bridge wire from the square onto the rectangle in the C6 area?

Any insight would be most appreciated. Cheers!