HDMI TO VGA BAD?

[kvnjcksn]

I just received my new ARpiCADE kit from Highscoresaves. I opted for the complete 2500+ horizontal game pre-programed setup with a brand new RPi 3B+. Just assemble and play.

I have a nice Gauntlet Dark Legacy that has a freshly capped MEDIUM RESOLUTION Wells K7500 monitor in it. The Gauntlet PCB plays perfect on it and it has an original jamma harness. I verified the pinouts were the same on the harness as what is on the RPi Jamma before hooking anything up.

After assembling everything and powering up the RPi jamma boots and will play blind. The image on the monitor is scrambled.Everything else works as it should. After several attempts I still have the same issue. I disconnected the HDMI to VGA adapter and plugged a hdmi monitor directly into the Rpi and its perfect on the hdmi monitor. I tried running my laptop hdmi signal thru the on board converter and it also produced a scrambled image on the Gauntlet monitor.

Any ideas?

[kvnjcksn]

I just hooked a vga monitor up to the converter and it works.

[dee2eR]

There's no medium res setup built into ARpiCADE. Sounds like the hardware is working fine but doesn't suit the monitor. It would probably be possible to add medium res support to the software but I do not own a medium res monitor.

If there's a high or low res setting on the monitor chassis it could work, otherwise it would need a software configuration for medium res (prob possible but I cannot say for certain) OR a different monitor.

Sorry I don't have a quick and easy solution for this one.

[kvnjcksn]

The K7500 monitor specs call for resolution modes 640x400 (may be limited by CRT) and video bandwidth of 15MHz. I do have another cabinet with a vertical low res monitor in it but its a home use only Mrs Pac. I really want to keep it all original. I also have a Target Toss Pro Bags and I think it has a VGA monitor in it. it is due for a cap kit so I might pull it and drop it in the Gauntlet one day.

[dee2eR]

The Pi can be configured to run 640x400 @85Hz (or 640x350@85 or 720x400@85) in DMT mode, but I suspect 85Hz would be an issue for medium res arcade monitors. There's probably custom resolutions to be found that could do it but as I don't have the hardware I can't really experiment with it.

I agree, don't ruin your original Ms Pacman (although if you're happy with 2 and 4 way games only, a non destructive plugin JAMMA conversion harness could be used without destroying a nice piece of history), dedicated original complete cabs are better kept original in my eyes (it's different when the cabs were converted long ago by operators and original parts are unobtainium, your Ms Pacman sounds like its probably in top condition).