RGB bypass mod

speedlolita · Nov 1, 2012

Thank you for the clarification.

DANIPSX · Aug 31, 2013

I just cut the tree cables in my Aes rev 3-6, and now the rgb image is perfect!. I have a neoblitz on my Aes, but I like more rgb output!.

st dragon · Nov 30, 2013

No problem!

c0dehunter · May 2, 2014

I have a 3-5 Japanese AES 140XXX system, and I see the checkered board pattern (specially on the blue SNK Logo, similar to the image that Xian Xi posted a while back)

Do I need to do the RGB bypass only?

Many thanks.

Xian Xi · May 3, 2014

c0dehunter said:
I have a 3-5 Japanese AES 140XXX system, and I see the checkered board pattern (specially on the blue SNK Logo, similar to the image that Xian Xi posted a while back)

Do I need to do the RGB bypass only?

Many thanks.

Yes, If you are using RGB.

c0dehunter · May 3, 2014

Thanks Xian Xi. If I want to keep the composite, how would I do it?

Here is an Alternate method I did on a 3-5, this is mod was by customer request.

If you'd like to keep composite video you can leave the 6.8k resistors, 4th cap for composite (says sync in pic) and leave the 75ohm resistor instead of putting a jumper.

One important thing to note is that on revisions 3-5 and 3-6 a bypass mod isn't really needed as they have brighter RGB output than previous revisions. This is due to SNK using the recommended cap/resistor combo by Sony. On 3-5 and 3-6 it is 470uf caps with 75 ohm resistors, on previous models it is 100uf caps with 68 ohm resistors.

Xian Xi · May 3, 2014

c0dehunter said:
Thanks Xian Xi. If I want to keep the composite, how would I do it?

Just do the same as the picture that that text was from except leave in the 6.8k resistors and the bottom right cap and bottom 75ohm resistor.

Green Beret · May 5, 2014

I did the mod on my 3.3 and image looks like digital. Very bright with vibrand colors without bleeding. Artifacts of any kind FREE. To show propely on a common crt monitor had to turn it black and white.
On my BVM have put contrast to minimum levels near the zero point and image is perfect. I can change preset by pressing just one button though so not in a hurry to put resistors on RGB.
This mod is highily recommended, signal is equal quality with my cmvs.

EDIT: Image quality is clearly better than my cmvs

ToD_ · Jun 10, 2014

Over 10 years ago MKL performed the RGB mod on my AES. At the time I lived in Europe and it worked as intended on my TV, except that the image was extremely bright. Lowering the contrast took care of this issue. I'm assuming this happened because no resistors are in place.
A few years later I ended up moving to the United States where, as we all know, TVs with RGB inputs are non-existent. I left my AES in Europe until recently as I finally bought a Sony BVM screen. Upon connecting my AES using a Scart -> BNC cable I noticed the image was extremely bright again. After lowering the contrast I'm left with an image where all the lighter details are crushed. I figured adding 100 ohm resistors to the RGB lines (in the cable) would do the trick but it doesn't seem to help at all. I must be doing something wrong... Does anyone have an idea what I can do to resolve this issue? It would be much appreciated.

Edit: Never mind. Got my issues sorted!

Firehawk · Nov 25, 2014

Thanks this thread gave me a lot of info.
I have a rev. 3-6 and had the vertical stripes. The only thing I did is cut the traces and the stripes are gone. Very nice.

willys_82 · Oct 20, 2017

MKL said:
The grid pattern/vertical striping is limited to revision 3-6 because on this revision there is an area called "NTSC only" and the RGB lines are split before they go into the RGB encoder and sent to this area:

http://img215.imageshack.us/img215/9176/aes36be1.jpg

The problem is that these traces run under the clock signal for the encoder and cause some weird interference that shows up as the infamous vertical striping. If these traces, which are totally useless anyway, are cut/lifted from the PCB the striping effect disappears and you get a flawless RGB picture. Earlier revisions don't have these split RGB traces and consequently no striping/checkerboard effect whatsoever:

http://img85.imageshack.us/img85/2975/aes35yl1.jpg

That gamesx article fails to explain the phenomenon and claims that revision 3-5 (the '126000 serial') has a partial striping effect ('checkerboard'), i.e. better RGB than 3-6 but worse than the preceding revisions, which is simply false.

Revisions 3-5 and 3-6 have a brighter RGB output as a result of different values for coupling caps and resistors but this obviously doesn't "dramatically decrease the RGB quality". In fact the new values (470uF/75ohm vs. 100uF/68ohm) are what Sony recommends. In the end the difference between the darker RGB of the earlier revisions (NEO-AES, AES3-3, AES3-4) and the brighter RGB of the later revisions (AES3-5, AES3-6) is trivial and can be compared to a supergun setup with adjustable RGB pots where some will prefer the picture a little darker while others a little brighter.

Hi,

I have a problem with my japanese Neo Geo Aes (AES3-6 motherboard). There are a sort of scanlines effect and jailbars present in most graphics except for the text without movement and lifebars. I've checked some possible cut tracks withount succes and I'm running out of ideas... I also made the test with the universal Bios v3.2 and nothing wrong appear.
I haven't done the RGB mod but I ended up here because of the jailbars and motherboard.

This is a video I make so you can see in detail what I'm talking about (it's connected to the TV with composite:

https://youtu.be/ekYIfWj9AlU

Please let me know if think of something or where should I check.

Thanks

willys_82 · Oct 20, 2017

Hi,

I have a problem with my japanese Neo Geo Aes (AES3-6 motherboard). There are a sort of scanlines effect and jailbars present in most graphics except for the text without movement and lifebars. I've checked some possible cut tracks withount succes and I'm running out of ideas... I also made the test with the universal Bios v3.2 and nothing wrong appear.
I haven't done the RGB mod but I ended up here because of the jailbars and motherboard.

This is a video I make so you can see in detail what I'm talking about (it's connected to the TV with composite:

https://youtu.be/ekYIfWj9AlU

Please let me know if you think of something or where should I check.

Thanks

RGB bypass mod

speedlolita

n00b

DANIPSX

n00b

st dragon

n00b

c0dehunter

Tarma's Gun Polisher

Xian Xi

JammaNationX,

c0dehunter

Tarma's Gun Polisher

Xian Xi

JammaNationX,

Green Beret

Fio's Quartermaster

ToD_

n00b

Attachments

Firehawk

n00b

willys_82

n00b

willys_82

n00b