Display Washes Out After a Couple Minutes

[bobojijio]

Hardware: RaspberryJamma, Pi 3b+
Running: Arpicade 3.82

When using all of the (HSS) purchased hardware the screen initially looks fine but after about 3-5 minutes the picture washes out/fades to a red color (see attached). Removing and reseating the VGA end of the HDMI-to-VGA adapter into the RaspberryJamma board restores the picture for another 3-5 minutes.

Troubleshooting steps:
* The Jamma side is wired into a CGA-to-VGA converter and into a VGA monitor. Other Jamma boards do not fade.
* If the same monitor is plugged directly into the HDMI-to-VGA adapter it shows fine.

Any thoughts as to where I should troubleshoot the signal? I don't have a CGA monitor to test directly off of the Jamma side and further isolate the issue.

You've built a nice piece of hardware - thanks for all of your hard work and dedication

-Rob (Bobojijio)

[dee2eR]

I haven't seen this happen before. If I understood you properly you have an extra video converter in the signal chain? It's possible the CGA to VGA converter is the issue, even if it's not you will get much better results without a CGA to VGA conversion - best to plug high res monitors into the HDMI to VGA DAC directly and change the software to output high res natively.

If I've misunderstood you and I'm way off let me know. This is not something I have seen or heard of a RaspberryJAMMA doing before even in instances where a DAC has failed so I'm at least partially guessing what is going wrong.

The other candidates for the failure would be the DAC (I haven't seen or heard of one failing in this way), or the RGB amp on the RaspberryJAMMA (haven't even heard of one failing at all yet). I guess the Pi could also have some sort of fault but I wouldn't think that was the case. Nothing else should effect the picture, especially the colours.

Weird one. Hopefully this helps.

[bobojijio]

I have a 6-in-1 switcher as well in the cab which is the reason for the CGA-to-VGA adapter, otherwise I would plug directly into the DAC directly as a more permanent solution. I left the monitor plugged into the DAC for the last day and haven't had any issues but as soon as I feed it through the JAMMA / CGA-VGA / Monitor it exhibits the symptoms again. My other JAMMA boards (60-in-1, Ms. Pac Man Reunion) do not exhibit any of these symptoms going through the above chain.

I originally left the 6-in-1 out to simplify the equation because the issue presents itself even in the absence of the 6-in-1.

It seems like the Pi and DAC are working fine, but I would like to plug the DAC back into the JAMMA so that I can enable the 6-in-1 again.

[dee2eR]

What CGA to VGA are you using? You may be able to run the Pi into it at a different resolution with more luck. The default ARpiCADE config is using a few different low resolutions and changing them on the fly as needed so maybe having just one res will simplify things a bit.

It may be worth trying the 240p only (more accurately no interlaced modes - it still uses multiple resolutions) mode if you need to run through the scaler, or depending on what it is it may pass through a high res signal.

Alternately can you bypass the CGA to VGA and still use the 6 way switcher some how? Pretty sure the 6 way switch won't be doing anything to the video signal.

[bobojijio]

I'm using a GBS-8200 (https://www.amazon.com/gp/product/B00F1 ... UTF8&psc=1). I have the Pi set to display at the lowest resolution it'll go. I'll post the actual config line when I get back to work, but I can tell you that the line that is on the bottom of the block is the one that I uncommented. If you can think of any particular configuration settings that might do the trick I'd be more than happy to give it a go!

I'm fairly certain that the 6-in-1 doesn't do anything to the signal as I get the same results with it in-line as I do with it removed. I'll see if I can scrounge up a monitor that accepts CGA to take the converter out of the mix. The cab was a fresh fabrication with a VGA/DVI Dell monitor in it so I don't have any legacy wiring or native CGA capable gear. They installed a 60-in-1 board in it and wired the monitor directly to the board instead of using JAMMA CGA, so I had to install the CGA converter in-line before expanding.

Thanks again for an awesome product. My coworkers and I are having a ton of fun with it!

-Rob

[bobojijio]

The observed issue occurs with "hdmi_mode=1" enabled in config.txt. The observed issue does NOT occur with "hdmi_mode=6" or "hdmi_mode=8". In a vertical cab with vertical game roms, I prefer mode 1 as it shows everything full screen.

Everything appears to work in isolation; I think it's a combination of resolution changes, refresh rates and signal switching that is causing the issue. With the above configuration, immediately after turning the pi on you can vaguely see vertical scan lines waving back and forth across the screen.

I'll keep playing with the video settings and will post back if I find a configuration that works for the Pi, with the RaspberryJAMMA DAC, through a GBS-8200 to a digital monitor.

Thanks again for your help dee2eR!

[dee2eR]

It's a shame your monitor doesn't have a second VGA input that would allow the RaspberryJAMMA to bypass the upscaler while allowing other boards to use it. Any chance the DVi input is analog wired and can be VGA with a plug adaptor? If the monitor auto switches based on signal that could work, maybe...

I have one of those scalers somewhere but I haven't seen it since I moved. If I happen to find it I will see what I can do with it. Thought they could pass through VGA but I'm probably wrong, I haven't used mine in years.

Best results in your situation without the 6in1 would definately be from the DAC VGA out directly into the monitor on Mode 1 but with the signal having to go through the 8200 I'm not sure what the best solution will be.

What else is the 6in1 for? IF the games are well emulated on Pi do you need it and the scaler at all? (I realize this is probably not the direction you want to go but I'm throwing ideas around as I don't know how else to help at the moment)