CRT screen appears very dark after installing with EDID emulation enabled

[Demilich]

Ok so I'm following this guide http://geedorah.com/eiusdemmodi/forum/viewtopic.php?pid=1053#p1053 and have gotten as far  as enabling EDID emulation and hooking up my CRT to my computer via DVI-I > VGA > Extron 201 rxi > BNC cables into the Ikegami CRT monitor. At first it looked like I was getting a black screen, but I turned the brightness almost all the way up and saw this: https://imgur.com/a/YgM5FAw

It's way too dark and the colors seem very off, as you can see. The monitor looks really nice with input from a console, so what am I doing wrong? My GPU is a Radeon R9 350, which also works fine if I hook it up to my LCD monitor. Could it have something to do with the Extron? It seems to be working properly and displays the correct frequencies. I did find it a bit strange that vmmaker lists my only analog output as Analog_0-VGA since there's no VGA port on the card, but I'm not sure if that's relevant to my issue. Any ideas?

[Calamity]

The "Analog_0-VGA" label is normal since from VMMaker's point of view it can't tell it's not a VGA. You'll have a separate ouput listed as Digital DVI, corresponding to the same connector, on its digital working mode.

Anyway, the issue could be related to the voltage of the sync lines. The VGA and the RGBHV standard differs in sync voltage values. If the CRT is compensating the brightness based on peak sync voltage, it will be too dark. Just a guess.

[Demilich]

Thanks for the reply, Calamity. Do you think it would be worth a try to buy a VGA to BNC cable and use that instead of the Extron? Is there anything else you can think of that might fix this?

[digitron]

Thanks for the reply, Calamity. Do you think it would be worth a try to buy a VGA to BNC cable and use that instead of the Extron? Is there anything else you can think of that might fix this?

I'm also curious about this, can I just go from vga to bnc or do I need an Extron thingy in the mix? (PVM-14L5)

[Demilich]

Someone on r/crtgaming suggested enabling SoG on the extron and internal sync on the monitor, but that just gives me a green screen instead of a dark gray one.

Desperately in need of help here, as I bought this PC just for groovyMAME/retroarch. I've gone ahead and ordered a VGA to 5BNC adapter- that should work in theory if I enable csync output in vmmaker right? Pretty much just taking stabs in the dark at this point. If I can find another RGB capable monitor at a reasonable price, I'll probably just buy it so I can determine whether or not it's the monitor that's the issue.

[donluca]

Shooting in the dark here, but some arcade monitors are able to "sense" the incoming signal and adjust the sensibility so that a "consumer" (0.7Vpp IIRC) signal it is displayed with the correct brightness and if the signal is an arcade one (5Vpp IIRC again) it adjusts itself again.

What might happening here might be that the source is outputting a signal slightly stronger than consumer grade and the monitor is interpreting it as a signal coming from an arcade board which makes it very very dark.

Although this might sound counter-intuitive, try putting some resistors across your rgb and sync lines to lower them down a bit and see if that works.

Otherwise you'll need a video amplifier to get to proper arcade signal strength.

[Arroyo]

Do you think it would be worth a try to buy a VGA to BNC cable and use that instead of the Extron?

I would try this, and you can also buy this:


If you can’t get C-Sync to work.

[Demilich]

Well, some decent progress was made today but there still seems to be some weirdness going on. I got a VGA to BNC5 cable and tried using that instead of the Extron. This is the result: https://imgur.com/a/ZheLqey

Besides the image being off center and the weird slope at the top left which seems like a sync issue, there's also some really intense interlacing judder going on that makes it painful to look at. 480i looks pretty terrible on this monitor in general, but this is on another level from anything I've seen, as the image is shaking so hard it looks like there's an earthquake happening. Bizarrely, at least to me in my ignorance, it makes no difference whether either sync wire is plugged into the monitor, or whether csync is enabled in VMM. It looks the same no matter what I change, although of course if I enable ext. sync on the monitor then it completely loses sync and starts rolling vertically.

One thing I did notice is that a pin is missing form the VGA side of the cable: https://imgur.com/a/X7eQTOz. Could this be having a negative effect? I would certainly imagine so.

Is this just what I should expect the initial 480i image to look like? I'd imagine not, and I'm really perplexed about plugging in a sync cable/enabling csync making no difference. As always, I hugely appreciate any insight you guys can provide. It does feel like I'm getting closer, so that's cool at least.

I would try this, and you can also buy this:

If you can’t get C-Sync to work.

So this device will combine the HV sync lines into one csync line? That seems like it may be helpful here, but idk.

[Arroyo]

So this device will combine the HV sync lines into one csync line? That seems like it may be helpful here, but idk.

Yes, I’m using it in a PVM I have and it works fine.  What’s the model number of your Ikegami?

Do you see a vertical hold knob anywhere?

[Demilich]

Thanks for the info, Arroyo. Any particular reason you go with that instead of enabling csync in VMM? Pre-5000 series card I'm guessing?

The Ikegami is a TM20-17R. I don't think it has a vertical hold knob, but there is a pot on the inside for vertical hold. Do you think I should try messing with that?

Pretty unrelated, but here's a nice guide KyaDash from r/crtgaming made that covers what most of the pots on this family of monitors do: https://imgur.com/gallery/udtbh3E

Should I return the cable due to the missing VGA pin? That seems like it could cause serious problems, but again idk.

[Demilich]

Well, I went ahead and opened up the monitor up to mess with the pots. V.hold made no meaningful difference, but H. hold fixed the slope that was happening on top. I also adjusted H. phase to move the image closer to the center: https://imgur.com/a/bofxPQO

It seems like I'm getting close to being able to move onto the next steps toward getting some emulators running, but I have some remaining concerns:

- Why is the image so squashed horizontally? I could mess with the geometry settings of course, but is this normal/expected?

-The extreme shakiness is still there. For now I'm chalking this up to the monitor just being bad at interlacing, because the 480i test in 240p test suite looks awful as well.

- How am I even getting a remotely stable image while having csync disabled in VMM and no sync cable plugged into the monitor? Both of these factors appear to make no difference. What am I missing here?

- The aforementioned fact that the VGA side of the cable is missing a pin, and whether I should return it.

[Arroyo]

Thanks for the info, Arroyo. Any particular reason you go with that instead of enabling csync in VMM? Pre-5000 series card I'm guessing?

I have a few TV’s at the moment, and the PVM is the only one that I’m currently using that uses Composite Sync.  I have a consumer TV that I use Component and don’t want to switch between C-Sync, easier to just switch cables.

The Ikegami is a TM20-17R. I don't think it has a vertical hold knob, but there is a pot on the inside for vertical hold. Do you think I should try messing with that?

I imagine, but just read your post so maybe not.

Should I return the cable due to the missing VGA pin? That seems like it could cause serious problems, but again idk.

I think that’s not an issue:



I tried quickly looking for a Manual on your monitor, only found this so far:

https://archive.org/stream/TM142020202030RHOperationManual/TM14-20_20-20_20-30RH%20Operation%20Manual_djvu.txt

Can you get a stable signal from another source, say a DVD player on a different input?

[Demilich]

Can you get a stable signal from another source, say a DVD player on a different input?

Yes, it works fine with my SNES other than this annoying squiggly line that I think is due to bad capacitors:

I've seen this happen with the PC connected as well, though it seems less frequent.

[Arroyo]

For a few bucks I’d try the BNC Y-connector and see what you get.  That will help you isolate if this is a software issue. 

[Demilich]

For a few bucks I’d try the BNC Y-connector and see what you get.  That will help you isolate if this is a software issue.

I think you're right, as I just noticed this is what the image looks like if I drag the browser over, regardless of any changes I make to V. hold: https://imgur.com/a/pSzOWQ3

It looks like this whether I have a sync cable plugged into the monitor or not, and whether csync is enabled or not. Any reason why the csync option in VMM wouldn't work?

It really felt like I was getting close too...

I did forget to mention earlier that according to VMM and Windows the card is actually a R9 360M, not a 350 like I thought.

[Arroyo]

That’s a weird image.  I’m guessing that you need to start over on the software side but someone like Calamity could comment better. 

I think I remember getting an image like that.  I’d try uninstalling the drivers and starting over.  I had to do this a number of times before I got it right, so you’re not alone in the trial and error.