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Naomi won't boot some games but works fine with others

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trashedcabs

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This naomi motherboard has issues booting random games. Both the game and the game's test mode sit at a black screen when you try to launch them. The netdimm I'm using is fine, it can boot all games on another motherboard. Unfortunately I don't have many cart games, and the few I do have work fine on netboot as well.

I was getting an intermittent IC35 RAM error which I thought was the problem, but after swapping that chip the problem still occurs.

Here's a few games I can boot just fine and run for hours with no issues:

Virtua Striker 2 ver 2000 (cart and netboot)
Heavy Metal Geomatrix (cart and netboot)
Cosmic Smash

Some games I can't boot:

Azumanga Puzzle Bobble
Border Down
Virtua Tennis

Any ideas? I would guess another RAM pair, maybe?
 
  • Did you run a RAM check within the setup menu? All show okay?
  • Do you use a Region Free BIOS?
  • Are the DIP settings are the same as on the other board?
  • Is this a noami1 or noami2? (the other setup you run: is it a noami1 or 2?)
  • can you enter SETUP after black screen?
  • if no game is insert: the naomi boots up fine?
  • how do you power your naomi?
Just some guesses ... sadly i have no solution (yet) for your problem.
 
how are your 5v and 3.3v readings? I know naomi is very very finicky when it comes to voltage
 
I have multiple Naomis that have issues booting games with a 4.01 DIMM board attached. Doesn't matter if it's netboot, GD or CF. They won't even show the Naomi logo on boot, just a black screen. I cut the power and try again. I sometimes have to do this up to five time. Once it boots, it's rock solid. Never had one issue during gameplay.

Regular carts work every time.

The voltages are in spec.

I suspect it's the caps on the Naomi motherboard, but so far I haven't tried recapping one. It's such a monumental task.
 
It's not the fans.

EDIT: @trashedcabs, does your motherboard boot to the Naomi Network System screen every time?

Maybe my issue is different. Nevermind then.
 
Last edited:
Orakelschaf said:
  • Did you run a RAM check within the setup menu? All show okay?
  • Do you use a Region Free BIOS?
  • Are the DIP settings are the same as on the other board?
  • Is this a noami1 or noami2? (the other setup you run: is it a noami1 or 2?)
  • can you enter SETUP after black screen?
  • if no game is insert: the naomi boots up fine?
  • how do you power your naomi?
Just some guesses ... sadly i have no solution (yet) for your problem.
Click to expand...

Yes, I have performed all basic troubleshooting steps for the naomi. To clarify: the two motherboards are on the same exact setup. One works fine, the other has this issue.

-RAM check done many times, all good now every time. Previously had IC35 bad, I replaced it and it has been testing good since.
-Yes, I use the multi-region BIOS. I just verified a good burn in my programmer again.
-DIP settings are identical
-Both are Naomi 1, same board revision
-No, the system becomes hard locked at the black screen.
-Yes, the naomi boots fine with no game. Again, the bad naomi will boot some games and play just fine for hours.
-I use a Sun Lindbergh PSU, voltages dialed in to 5.08 and 3.32v at the filter board.

nem said:
I suspect it's the caps on the Naomi motherboard, but so far I haven't tried recapping one. It's such a monumental task.
Click to expand...

Ken mentioned that the 10uf caps seem to be going bad on Naomi boards now, and I did repair one recently that was missing audio caused by bad caps in the audio path. I checked the 10uf caps on this board near the cart slots and they are all reading high ESR. I did replace a handful, but it hasn't made a difference. I need to order some more SMD caps and then I will replace the rest.

And yes, it boots to the network system screen every time.

I have a feeling some games are accessing a portion of memory that some games aren't using, which is why those boot OK but not others.
 
Thanks a lot for the detailed information!
  • I guess at that point i would do a full recap just to make sure its not the caps, just listen to some nice music and it is done in no time :) - And please let us know if this caused the issue
  • did you measure the 3-4 voltage points on the board itself just to make sure voltage is fine?
  • all the stuff i can find about the issue is power related. Compare the voltage points on both naomis please. - It can be a caps issue.
  • Just to make sure: you use the same PSU on both naomis?
 
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