NEO-AES w/o daughter board not working

[DanAdamKOF]

Hi guys, posting this on behalf of SkinnyThor, a buddy of mine whose account is too new to create topics. I've tried to assist but my limited knowledge of AES was quickly tapped out, please read and help, thanks y'all!



I recently bought a Neo Geo AES that I saw pop up on Ebay, US version SN 16,245, and I ordered what I thought was the appropriate power supply at 5V3A. When it came in, this is the screen I was greeted with http://imgur.com/zP5H8lU

When I turn it on with a cartridge I get the same screen, but also a steady clicking noise.

Since the only way to make sure was to open it up, I went ahead and did that http://imgur.com/LDbP5e2

Here's an album with all the pictures I took of the motherboard. http://imgur.com/a/dmkBc

It's for sure the right PSU, so there must be something wrong elsewhere. How would I even go about testing this thing? I do have a friend's voltmeter I can use, but I'm also open to sending it away to be repaired if it's too hard a fix.

Anyone have any thoughts on this? If it's a lost cause I can return it and get a refund, I'd just really hate to have to do that.


Sent from my iPhone using Tapatalk

 

[nam9]

Hopefully its a PSU issue.. Should take a 5v 3A with negative tip. 2.5A may be too low?
I'd try and find a good quality PSU rated 3A+ and see if that changes things...

Lot of tips in this post.

 

[Xian Xi]

That's a PSU issue. It usually happens when the power supply is shit and it's one of those cheap ones that aren't even close to it's rated output. Most likely it's rated at 3A but when it outputs like 2A the voltage drops below 4.6v. Usually anything below 4.75v you get problems, of course 5.00v would be optimal.

 

[SkinnyThor]

Like I said in the power supply thread but forgot to mention in this thread, I did get a new PSU that I hoped would work. I got the 5V3A PSU from here http://retrogamecave.com/#/shop/4577155957/neo-geo-power-supplies/10160961

The power supply itself is much larger than the first one, and is labeled as a pro-pow PSU. The same problem persists, but it is slightly different in that it more often shows garbled graphics in black and white as opposed to color. I'll make a video of everything when I get back from Thanksgiving dinner tomorrow.

If it really is just a PSU issue I may just have to bite the bullet and buy a OEM PSU even thought they're $80+.

 

[Xian Xi]

Test the voltage in the AES on one of the TTL chips near the memory card slot. If the voltage is correct then you can move to another possibility.

 

[SkinnyThor]

Here's the video that I promised.

https://www.youtube.com/watch?v=Jy6XuYccrFQ

My multimeter needs a new battery, so when I grab that I'll test the voltage.

 

[Xian Xi]

Looks like it's in watchdog. Was there a slight clicking sound?

 

[SkinnyThor]

Yes, there is a slight clicking noise when I use the other PSU I have an put a cartridge in. I can make a video of that if you need me to as well.

 

[HeavyMachineGoob]

You sure this isn't actually a 9v Neo Geo? Mine does the same sort of thing with a 5v PSU, dark clicking garbage screen.

 

[shadowkn55]

You sure this isn't actually a 9v Neo Geo? Mine does the same sort of thing with a 5v PSU, dark clicking garbage screen.

According to the board pics in the first post, it's definitely a 5v system.

 

[SkinnyThor]

Here's a video with my secondary power supply that makes the slight clicking noises.

https://www.youtube.com/watch?v=K147JZ3T2LQ

I was researching some old threads, and if it really is a problem with the watchdog timer, that means its a faulty RAM, BIOS, or CPU correct? Does that mean I need to pull out the board and look for any broken connections? Or, at this point should I look into finding someone to send this to who can fix it.

 

[Xian Xi]

Here's a video with my secondary power supply that makes the slight clicking noises.

https://www.youtube.com/watch?v=K147JZ3T2LQ

I was researching some old threads, and if it really is a problem with the watchdog timer, that means its a faulty RAM, BIOS, or CPU correct? Does that mean I need to pull out the board and look for any broken connections? Or, at this point should I look into finding someone to send this to who can fix it.

Get the pinout for the bios and use a multimeter to make sure all the connections are 100%, if there's a broken connection somewhere then fix it. If all connections are 100% then it's either the WRAM, BIOS or CPU. Most times it's usually a bad trace from the WRAM or someone botched a bios install(if bios has been changed/replaced).

 

[wyndcrosser]

I had something similar, it was a bad trace, not a watch-dog issue. KPJ fixed it for me.

 

[SkinnyThor]

OK, I messaged KPJ at Neotropolis. I think at this point the repair is a little above my current level of knowledge. Here's hoping that he'll be able to help me out.

 

[DanAdamKOF]

Just want to thank everyone for helping my newbie friend out.

 

[SkinnyThor]

Just wanted to give an update to everyone that gave advice. It's being sent to the group over at Neotropolis. Hopefully they'll have a definitive answer.