having sync problems on XRGB-3 with NeoGeo

[todosnk]

Hello everyone!
I am new on this forum and really enjoy reading the posts and tons of information regarding the XRGB.

Lately I bought one XRGB-3 which I just received a few days back. I am having some sync problems and hopefully someone could tell me how to fix these?

My setup:
-XRGB-3 with english firmware update
-NeoGeo AES with euro RGB cable and adaptor for GAME IN
-a SONY PC screen connected to the XRGB via VGA for B1 mode

the image looks great, I love these scanlines and the only issue I have is that on the top of the screen the image is wavy. Also when I turn AFC mode to 5 the screen blinks a lot and can hardly see anything. Only on AFC set to 0 the image is stable and sharp, but then I see that the upper part of the screen the image is waving.

Does anyone know how can I correct this? Is this normal or simply my PC monitor is unable to handle the image properly? I plan to buy a LCD TV shortly hopefully I will not have the same problem there .

Also, are there any recommended settings for this setup?

I have attached a screenshot to see the problem:

http://www.flickr.com/photos/flamenquin2001/4910327010/

Hopefully someone can guide me on tihs
Thanks!

[Fudoh]

Has been discussed a few times before, but without a real conclusion which part's to blame.

You can try to add a LM1881 sync stripper. You can try both composite sync output from the LM1881 into the front Scart input and seperate H/V syncs into the back SubD15 input of the XRGB.

Nevertheless it's possibel that it won't work due to the NG's ouput being 59.15Hz instead of 59.94Hz Standard NTSC. Same problem with your upcoming NTSC. There's no way to tell if it will accept VGA so much off the 60Hz standard without trying.

B0 should decouple the input from the output framerate. Just out of interest, does everything work in B0 ?

[todosnk]

Hi Fudoh!
Thanks for the quick reply. On B0 everything looks just fine.
In addition, on B1, setting AFC to 0 I get a stable image perfectly drawed, except for the screen upper band which is moved like the screenshot I posted before. It seems that when I increase AFC parameter value, the image becomes better and better, but then it flickers a lot, and it is unplayable because of the flickering. For example on AFC set to 5, it flickers, but them the edges of the image and all are perfect when displayed (according to wiki AFC to 5 is a recommended setting for NeoGeo).

How could I get this LM1881 sync stripper? Is there anywhere in Spain or Europe where I could buy it?

[Fudoh]

It's an IC you locally buy, but you usually have to solder it into your RGB cable yourself (or have it done).

[todosnk]

Thanks Fudoh,
I am really not familiar with these, luckily there may be some member in the forum who can make it or sell it to me. I will look around a bit more, hopefully someone can help here
If I understand correctly, all I need is to have the LM1881 installed in my neogeo RGB cable, is that right?

[Fudoh]

all I need is to have the LM1881 installed in my neogeo RGB cable, is that right?

it's a possibility.

You could try another display to see if it's the XRGB that blacks out on higher AFC settings or just the monitor.

[todosnk]

I just tried it on a different PC monitor and I do have the same issue. The screen comes and goes for about 1 second every now and then.
I did modify Neo Geo internally so it can output sync like the earlier revisions, following instructions from this forum:

http://www.neo-geo.com/forums/showthread.php?t=215758

however I am still getting this not working.

I would appreciate if anyone could guide with some clear pictures me on how to solder the LM1881 to the NeoGeo connection, preferrably to the RGB-21 Euro>Japan converter which needs to be plugged in the GAME IN port of the XRGB-3, if this is possible