Naomi 2 Blinking Checkerboard Pattern

Morden

Somewhere in Europe.,
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Jul 5, 2005
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Yesterday my Naomi 2 played just fine. Today, when I tried booting up Virtua Fighter 4, I got a blinking checkerboard pattern, no sound and a whole lot of slowdown.

I did a quick search and people seem to think it's a bad processor that might need replacing, or at the very least, reflowing. Is there anything else this could be?

I'm powering it with a PC power supply, connected via Capcom I/O. I only run power and USB for controls through the I/O. I use sound and VGA outputs from the Naomi directly. It runs a Net DIMM as well. Here's a video of the problem:


Naomi games work just fine. Naomi 2 don't. The blinking is even visible in the game settings menu. When I go into test mode and choose the game options, even though it's just a white text against a black background, I can see the squares blinking.

P.S. - If it is a bad processor, is there someone near or in Sweden who'd be willing to fix this? The closest person I can think of is Raz, but I don't know if he's into that sort of thing. Any help would be greatly appreciated.
 
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pulstar

Mickey's Coach
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I always thought the checkerboard fault was down to the second GPU that the Naomi 2 has, which is why Naomi 1 games work fine but Naomi 2 games don't work. A reflow might help but as far as I know it's always a temporary fix and breaks again after a short period of time.
 

Morden

Somewhere in Europe.,
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I always thought the checkerboard fault was down to the second GPU that the Naomi 2 has, which is why Naomi 1 games work fine but Naomi 2 games don't work. A reflow might help but as far as I know it's always a temporary fix and breaks again after a short period of time.

This would suggest overheating, similar to the problems with some Xbox 360 models. The GPU itself isn't broken, but it won't stay soldered properly. Is that what's happening? I always thought both Naomi models had enough fans to cool everything. They're loud as hell.

Some people outright remove the fan pulling the air in. Supposedly, it doesn't make that much of a difference, as they're only useful in case of non-stop operation inside a cabinet. I connect mine to a TV. It's just sitting on the floor. It does have all of its fans however.

Would the GPU fail again after reflowing and a fan swap?

Update: This is the result of the RAM test.

IMG_20170909_141603.jpg
 
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pulstar

Mickey's Coach
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So, it looks like it could be two issues then. According to a post by AndyGeezer (4th post down) in this thread, it seems that because you're game is running slow and it has the checkerboard. Is IC117 a piece of RAM? Couldn't hurt to replace it at least and if that doesn't work try and reflow the second GPU and yes, it is a problem to Xbox 360 where the GPU is fine but overheating has caused a problem with the BGA connection and it needs to be reflowed.

Here's a link to that thread https://forum.arcadeotaku.com/viewtopic.php?t=18847
 

Morden

Somewhere in Europe.,
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Is IC117 a piece of RAM? Couldn't hurt to replace it at least and if that doesn't work try and reflow the second GPU

It is. It's a Samsung K4S161622H-TC60 16Mb H-die x32 SDRAM. Unfortunately, I don't have necessary equipment to deal with this, as a soldering iron alone just won't do. Not to mention the GPU. So again, if anyone in Sweden, Scandinavia or even Europe would like to help me out with this, I'd really appreciate it. I'm not expecting anyone to do any charity work, either.

Naomi2BadRam.jpg

Here's a picture of IC117. It seems to be soldered in place. I honestly have no idea why it would just die. The gunk on top of it looks to be ancient hot glue. Could this be a GPU issue as well, which Naomi 2 identifies incorrectly as a RAM failure? Does the Naomi 2 GPU even give an error in the test menu?
 

LegoSlug

Over Top Auto Mechanic
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It is. It's a Samsung K4S161622H-TC60 16Mb H-die x32 SDRAM. Unfortunately, I don't have necessary equipment to deal with this, as a soldering iron alone just won't do. Not to mention the GPU. So again, if anyone in Sweden, Scandinavia or even Europe would like to help me out with this, I'd really appreciate it. I'm not expecting anyone to do any charity work, either.

View attachment 46477

Here's a picture of IC117. It seems to be soldered in place. I honestly have no idea why it would just die. The gunk on top of it looks to be ancient hot glue. Could this be a GPU issue as well, which Naomi 2 identifies incorrectly as a RAM failure? Does the Naomi 2 GPU even give an error in the test menu?

Looks like you found the culprit. Any electronics repair shops where you live? You can tell them what you need done. Seems like you pin pointed it.
 

Geekman1222

Kula's Candy
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I have a Capcom VS SNK Millinium fight 2000 cart i got in unknown condition for dirt cheap that has a bad rom chip on it. Been meaning to fix it. Anyways if i ever used it it would just randomly stop working (i suppose when it accessed the bad rom). So its very possible thats your issue it just cant read something properly! You can get a new rom programmed to replace that one and just have them swapped.
 

Morden

Somewhere in Europe.,
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Looks like you found the culprit. Any electronics repair shops where you live? You can tell them what you need done. Seems like you pin pointed it.

Unfortunately, no. I live in a relatively small town. We had one repair shop, but people don't get things repaired these days. They just buy new stuff. The guy went out of business. Serves him right, though. He was charging insane amounts of money. One of my previous jobs was at a place manufacturing industrial security systems and other electronics. Back then, I would just take it to work, but that place is gone as well. It's a simple enough fix if you have the right tools, but again, I don't have the tools, so if anyone is willing to help, that would be great.

Geekman1222 said:
I have a Capcom VS SNK Millinium fight 2000 cart i got in unknown condition for dirt cheap that has a bad rom chip on it. Been meaning to fix it. Anyways if i ever used it it would just randomly stop working (i suppose when it accessed the bad rom). So its very possible thats your issue it just cant read something properly! You can get a new rom programmed to replace that one and just have them swapped.

Like I said before, it's a SDRAM chip on the Naomi 2 board itself. At least that's what Naomi's RAM test is telling me. The game data is fine, but the Naomi isn't getting that 16Mb from IC117. I hope that's the only issue with it. The symptoms are almost identical to the GPU failure, though.
 
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Geekman1222

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Like I said before, it's a SDRAM chip on the Naomi 2 board itself. At least that's what Naomi's RAM test is telling me. The game data is fine, but the Naomi isn't getting that 16Mb from IC117. I hope that's the only issue with it. The symptoms are almost identical to the GPU failure, though.

Oh woops LOL I did not catch that. Missing or Corrupted ram chips could likely also do that, lets hope thats the only thing wrong. Best of luck :D
 

Morden

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Well, since I was unable to find anyone willing to help me out with this, I've decided to attempt the fix myself, which looking at the scale of the surface mounted memory was a terrible idea. I have ordered a hot air gun, but one it came, it was ginormous. The thing that took the longest was the replacement chips. One package got lost and the other took weeks to arrive. Anyway, the chips arrived today, and wouldn't you know, they don't have the exact same markings on them. I needed K4S161622H-TC60, but got K4S161622H-UC60 instead.

The question is, what's the difference? The datasheet only lists it as K4S161622H, without the suffix. If I were to even attempt this, I have to be absolutely sure it's the right chip for the job.
 

Kid Panda

The Chinese Kid
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12,514
that glue is what was holding the wire for one of the cpu fans. if youre going to do this, make sure to use lots of flux. good luck. replace your fans btw.
 

Morden

Somewhere in Europe.,
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that glue is what was holding the wire for one of the cpu fans. if youre going to do this, make sure to use lots of flux. good luck. replace your fans btw.

The fans are working, but are noisy as hell, which as far as I know is "normal". I have a Naomi in a pretty much mint condition, and it sounds about the same as the pictured Naomi 2. Besides, I wouldn't know where to get replacement fans, if they weren't the exact match. The CPU one has a pulse output, thus three wires. I might look around, but it's pointless until I fix the board, but most likely I'll fry it. I took another look at it today, and seriously, I don't think I'm capable of doing this with the equipment at hand.

The question still remains. Are the TC60 and UC60 interchangeable?

Another question is, having giant hot air space cannon, will I be able to do this at all? I'd have to work without magnification, for starters. Second problem are those tiny caps along the bottom row of the pins. Would they tolerate the heat required to separate the chip from the board? I can attempt desoldering braid first, but I don't really see this happening when done with an iron.
 
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