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Thread: Couple of faulty AES

  1. #1
    Bashful Neophyte

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    Couple of faulty AES

    Hello,

    I wonder if anybody could give me some pointers, I have 2 AES which I am restoring at the moment with an interesting number of video faults.

    #1 AES NEO-AES3-4

    This one looked like an easy fix, when I first saw the motherboard. The previous owner had cut the bios off and kept the legs to solder a socket on top of it for I guess a Unibios or something similar. Previous owner kindly left a fully work bios. When turned it on, it only displayed a white screen, flickered and made a clicking sound. My conclusion was bad bios installation.

    What I did is remove as delicately as possible (took me 2-3 hours) the socket, the previous legs and re-seated the bios. In hindsight I should have fitted a new socket, I've ordered some but they haven't arrived yet...

    After bios re-seat the console magically started and displayed the NeoGeo splash screen almost perfectly (see screenshots) however the intro scren of the game I use for testing, Samurai Spirits is all white with some garbage graphic displayed at the top. I can play the game, the sound is perfect, but the gameplay is plagued by white vertical bar. I tried cleaning the cartridge thoroughly but no changes.

    Here are some screenshots taken with a camera and a video captured though my framemeister.

    Funnily enough the framemeister does a really poor job with this system while my TV on its own works much better. Screenshots are captured using the TV.

    Neo Geo AES Bios re-seat by 470s, on Flickr

    Neo Geo AES Bios re-seat by 470s, on Flickr

    Neo Geo AES Bios re-seat by 470s, on Flickr

    Neo Geo AES Bios re-seat by 470s, on Flickr

    Neo Geo AES Bios re-seat by 470s, on Flickr

    Neo Geo AES Bios re-seat by 470s, on Flickr

    Neo Geo AES Bios re-seat by 470s, on Flickr

    Neo Geo AES Bios re-seat by 470s, on Flickr



    #2 NEO-AES3-5

    This one has an interesting problem, it basically looks like there are scanlines applied to the image when none are applied. There are also rainbow like artifact on the image but I'm not sure if it's because I'm using a composite signal. I need to build a new RGB cable for these Neos. Not all the image look bad as you can see from the video but the problem is there. Sound is perfect and you can play no problem. Again the Framemeister doesn't like that system either, looks better through TV directly.



    I think I found the origin of the problem, about 3-4 pin on the NEO-B1 chip appear to becorroded and it looks like some of the traces have been eaten away, probably a leaky cap earlier in its life? I just wanted to double check before I start operating it, if the NEO-B1 could be the culprit here and what would be the best course of action here? It's a very delicate repair and I'd probably do a bypass rather than trying to fix it in situ.

    Thanks for your help in advance
    Last edited by sabre470; 03-04-2018 at 08:08 PM.

  2. #2
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    Picture of the NEO-B1 chip for the #2 NEO-AES3-5 console:

    Neo Geo Horizontal Lines by 470s, on Flickr

    Neo Geo Horizontal Lines by 470s, on Flickr

    Neo Geo Horizontal Lines by 470s, on Flickr

  3. #3

    Neo Alec's Avatar
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    The Framemeister should be great. Makes no sense. Try downloading FBX's Neo Geo profile, and make sure you have zoom turned on.

  4. #4
    Timid Neo Newbie

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    Your AES #1 is a case of following traces from the cart connector pinouts downwards, look for the AES schematics. Or, if you have an oscilloscope check for pins activity - in this test the cart has to be inserted.

  5. #5
    Crazed MVS Addict
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    The 3-5 console is almost certainly something corrosive from the factory. The area around Neo B1 is frequently splashed with something corrosive. I’ve encountered this at least 6 times now on 3-5 and 3-6 consoles and most of those showed no sign of intrusion on the foam rubber feet. MobiusStripTech even found a corroded trace UNDER the Neo B1.

    The spots of corrosion are usually very tiny, like some chemical spatter from something nearby during production.
    Corrosion:
    https://i.imgur.com/CM9Qf3a.jpg


    Repair:
    https://i.imgur.com/UJlMXn7.jpg
    -El Duderino (not into the whole "brevity" thing)

  6. #6
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    Quote Originally Posted by tobisham View Post
    Your AES #1 is a case of following traces from the cart connector pinouts downwards, look for the AES schematics. Or, if you have an oscilloscope check for pins activity - in this test the cart has to be inserted.
    Hello, thank you for your guidance, I followed the traces from the cart connector but didn't find any cut traces so far. I corrected a few other mistakes on the board but still no changes. One interesting thing is that I built an RGB cable which works great on an AES NEO-AES3-6 but doesn't work on that board, the console either doesn't start (it makes kind of muffled noise) or it starts but I get only sound and no image. I've also put back that console to PAL for now to see if that was the issue.

    Questions:
    - Are their different version of the RGB cable?
    - Did I need to build one specific for that board?
    - Could there be a short somewhere?

    The cart connector is also different from any other Neo I've seen, basically on either side of the cart ports it is open, so wondering if contacts get lost there? Cleaned the card connectors a but no changes. The board is covered is some goo but no apparent corrosion.

    Thank you advance for your help

  7. #7
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    Hello,

    I have one more interesting issue to share on an AES NEO-AES3-3, on this one I suspect a Unibios job that didn't pan out, again...

    The console starts no problem and it start booting the game(s) but past the NeoGeo splash screen the screen goes black, also there is no sound at all though some static can heard on the headphones. Interestingly when I put the Unibios (3.2) in it, I can access the Bios (select+start) anytime even after the NeoGeo splash screen and the system goes black, I can reset it and all. Also this is a system with a Neo-Power board, so runs on 5V, bought a 5V adapter 2500ma and the image is fuzzy at best with that adapter. Tried a large regulated power supply on a slightly higher voltage (6V) and it works like a charm save for not booting any games fully. Confusing system...

    Sounds to me like a cart connector issue but I'm unsure as I cleaned it already, any thoughts?

    Thank you in advance.

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