AES video display problem

Breetai · Nov 3, 2009

Hey all.

I've got a stock AES with a video problem here. I'll let the pictures do the talking:

As you can see, the part of the picture displaying the Neo Geo logo is very distorted,
but the "Pro-Gear" part is coming in just fine.

These World Heroes need a hero to save their garbled graphics.
Can anyone be their hero? (no, I'm not gay... I just have a really lame sense of humour.)

As you can see, the bar at the bottom comes in fine, but the top layer is a mess.
It's like that in every game I've tested.

Sorry for the oversized photo, but I thought I should get some detail in there in case anyone here knows what they're looking at.
Any ideas on how to fix this problem?

A video connection problem, perhaps? Cartridge connector needs cleaning? Any other thoughts?

Thanks all!!!

PS: PLEASE no death threads for running an AES on a wide-screen!!! I know well the dangerous ground on which I tread here.

Xian Xi · Nov 3, 2009

Test another game first so we know for sure it's the AES.

I had a problem similar to that before twice. One time it was a broken trace to the LSPC and the other time was a corroded trace to the video ram.

Kyuusaku · Nov 3, 2009

I think C ROM A4 is stuck high which probably means a broken trace (they have TTL inputs). Start by looking at CHA board pin A18.

metallizer · Nov 3, 2009

you should try on another TV, maybe your set is not found of the NG video signal.

channelmaniac · Nov 3, 2009

metallizer said:
you should try on another TV, maybe your set is not found of the NG video signal.

Fail.

You have an address line problem on one of the ROMs... Dirty cart, dirty slot, or bad trace...

Clean the cart and slot. If that's not it then look carefully for scratched traces or junk on the board. The area around the cart slot is prone for junk being spilled into the slots. Look for gunk that needs cleaning... clean it and inspect the traces that were under it.

RJ

Breetai · Nov 3, 2009

Xian Xi said:
Test another game first so we know for sure it's the AES.

From my original post: It's like that in every game I've tested. I tested with 4 different games.

I had a problem similar to that before twice. One time it was a broken trace to the LSPC and the other time was a corroded trace to the video ram.

Any easy way to fix that, or does it involve soldering? I'll take a good look at the board when I get a chance.

Kyuusaku, thanks... I'll check that when I check the board next.

you should try on another TV, maybe your set is not found of the NG video signal.

As said, "fail". I have another, fully-functioning, AES to work with. It works fine.

You have an address line problem on one of the ROMs... Dirty cart, dirty slot, or bad trace...

Clean the cart and slot. If that's not it then look carefully for scratched traces or junk on the board. The area around the cart slot is prone for junk being spilled into the slots. Look for gunk that needs cleaning... clean it and inspect the traces that were under it.

RJ

Thanks RJ. Good logical ideas there. I'll give it a look.

Thanks all!!! I'll let you know the results whenever I get a chance to look (whenever that'll be!).

SNKNostalgia · Nov 3, 2009

99% of the time, it is a bad/dirty connection. Since it just seems to be the system, use a toothbrush with alcohol to scrub the system contacts and let it dry. Reinsert the carts multiple times, as this seems to adjust the contacts some. Also, try inserting carts and pull them up slightly so the contacts grip it better. Even though it must just be the system clean your carts while your at it.

Xian Xi · Nov 3, 2009

Did you buy the system like this or did you own it and this just happened?

What PSU are you using, and specs?

Breetai · Nov 4, 2009

Xian Xi said:
Did you buy the system like this or did you own it and this just happened?

What PSU are you using, and specs?

I bought it like this, knowing full well it had a video problem. This one is just an extra one, as I have another working AES.

The power supply is the official SNK one. Input: AC100V 50-60Hz 19VA/ Output: DC 10V 1000mA. It's plugged into a 100V socket, since... well, 100V is the norm here.

99% of the time, it is a bad/dirty connection. Since it just seems to be the system, use a toothbrush with alcohol to scrub the system contacts and let it dry. Reinsert the carts multiple times, as this seems to adjust the contacts some. Also, try inserting carts and pull them up slightly so the contacts grip it better. Even though it must just be the system clean your carts while your at it.

Yeah, I'll be trying that. The inserting cart and pulling it up trick works for cartridges on my Saturn, as the connection on the machine end of things there isn't so good.

Breetai · Nov 4, 2009

Well, I've tried cleaning the cartridge slot(s) on the main board and in the test games with q-tips and alcohol, then with a toothbrush and alcohol. Still doesn't fix the problem, unfortunately.

I'm not very familiar with the electrical components of the AES (or anything, really). I'm a bit green at this stuff.

kyuusaku said:
I think C ROM A4 is stuck high which probably means a broken trace (they have TTL inputs). Start by looking at CHA board pin A18.

Which one is the C ROM? I'm assuming I just follow the numbers until I get to number A4. Does this refer to the cartridge slot? Which row, if it does? Everything looks normal to me here.

channelmaniac said:
If that's not it then look carefully for scratched traces or junk on the board. The area around the cart slot is prone for junk being spilled into the slots. Look for gunk that needs cleaning... clean it and inspect the traces that were under it.

Well, everything looks fine. Forgive my ignorance, but what is meant by "traces". Are those the metal lines running around on the main board connecting everything? No gunk to be seen, as everything looks quite clean. The traces, as I understand them, seem okay.

Xian Xi · Nov 4, 2009

Try using a stronger PSU first. Some video problems are fixed pretty easy. Even though I'm pretty sure it's a bad trace I want to try and avoid soldering since you don't have experience with it.

You can use a PSU that has the following specs:

Negative tip polarity aka + ------(O----- - (You should see this on the PSU label, might be switch but as long as the negative is going to the O on the label it's fine)
+9v @ 2 amps (2000 mA)
+10v @ 2 amps (2000 mA)
+11v @ 2 amps (2000 mA)

If you have a Genesis or Megadrive PSU lying around you can try it as well.

Breetai · Nov 4, 2009

Yeah, I've got a Megadrive PSU lying around. Two, actually. The Mega CD gets one, too! You should probably specify that it's a model 1 Megadrive PSU, as the model 2 is different.

But, shouldn't the SNK PSU be fine?

Yes, I would like to avoid soldering. It's just an extra machine to eventually sell off to me, so I really don't want to put a huge effort into it. The educational aspect is nice, but the easiest way to get it working is best!

I'll try that tomorrow. Thanks.

Xian Xi · Nov 4, 2009

The SNK PSUs just like any other PSU can slowly drop off their output over time making it weaker and weaker. If the AES doesn't get proper power it can cause a lot of random problems, video being one.

Breetai · Nov 4, 2009

I didn't realize they got weaker over time. Makes logical sense, though.

Thanks

Xian Xi · Nov 4, 2009

This happens faster if you leave it plugged in even when not in use.

Kyuusaku · Nov 4, 2009

Breetai said:
Which one is the C ROM? I'm assuming I just follow the numbers until I get to number A4. Does this refer to the cartridge slot? Which row, if it does? Everything looks normal to me here.

The CHA board is the front connector and the pins are labeled on the PCB. A4 is the address line for the C ROMs, the actual pin you need to look at is A10 (not A18, I forgot we're talking about AES). Chances are slim you'll notice a bad connection unless there is visible damage to a trace. The PCB gets a lot of stress under the cartridge connector and a solder joint could crack. You'll need a multimeter set to continuity to test the electrical connection between the cartridge pin and the ASIC (custom chip) pin that's supposed to be driving it.

Breetai · Nov 5, 2009

Xian Xi said:
Try using a stronger PSU first. Some video problems are fixed pretty easy. Even though I'm pretty sure it's a bad trace I want to try and avoid soldering since you don't have experience with it.

You can use a PSU that has the following specs:

Negative tip polarity aka + ------(O----- - (You should see this on the PSU label, might be switch but as long as the negative is going to the O on the label it's fine)
+9v @ 2 amps (2000 mA)
+10v @ 2 amps (2000 mA)
+11v @ 2 amps (2000 mA)

If you have a Genesis or Megadrive PSU lying around you can try it as well.

Well, that didn't work. My good 'ol Mega Drive PSU powered up the Neo well enough, but with the same video problem.

I suppose the last option is to test for power all over the main board and acquire some soldering skills?

Xian Xi · Nov 5, 2009

Yup, all you can do is soldering now.

Breetai · Nov 5, 2009

Xian Xi said:
Yup, all you can do is soldering now.

Does anyone want to buy a Japanese AES with a video issue? It comes with all the hook-ups and two joysticks! I can throw in an generic early 90s era fighting game if you want. Well, that's if you consider something like Samurai Spirits, KoF '94, Art of Fighting or Fatal Fury to be generic.

Razoola · Nov 5, 2009

Have you actually looked over the solder side of the cart socket connections, maybe one on the connectons is bad. As a few others have said, this is deffo an address line problem.

Breetai · Mar 20, 2010

So, I traded this to someone I know over at pcenginefx.com for some PC Engine stuff (also with both joysticks and hook-ups, so it wasn't a bad deal I think). It hasn't been fixed, so if anyone else has any thoughts on this I'm sure it would be VERY MUCH appreciated by him. He knows of this thread and is much better at fixing things than me I am sure.

I have another AES for myself so I'm not at a loss.

Xian Xi · Mar 20, 2010

Like we all said it's gonna need some soldering most likely.

metallizer · Mar 20, 2010

Breetai said:
So, I traded this to someone I know over at pcenginefx.com for some PC Engine stuff

Hopefully it was not dean (d-lite).

Xian Xi · Mar 20, 2010

metallizer said:
Hopefully it was not dean (d-lite).

LOL

Breetai · Sep 1, 2011

metallizer said:
Hopefully it was not dean (d-lite).

I just handed it to Tatsujin for some loose PCE stuff and some KFC chicken. I forget what he said he did with it.

Is that a new record for a delayed appropriate response?

AES video display problem

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