Need Some Naomi 2 Help

yagamikun

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I appreciate any and all help, but please read the entire post/thread before responding. :)

Problem:

Naomi 2 boots to any game inserted no problem, but right before the game's title screen comes up a message appears on the screen that says "Entering Test Mode." The Naomi 2 will force enter the test menu but the Test and Service buttons on the Naomi 2 will not make menu selections as it should. So, basically, I get stuck in the Test menu with no way out.

Video:

I can't find this issue replicated anywhere on the internet in my searches here, arcade otaku, arcade-projects, or VAPS forums. I could have missed something, but I've seen nothing this specific.

History:
  • Purchased Naomi 2 with a Net Dimm CF Card set up for my AxunWorks Supergun. I got the Net Dimm with CF card mod from AxunWorks with my Supergun.
  • Naomi 2 has run every game I've thrown at it (16 games total), and has booted up just fine with absolutely no problems until I decided to clean it.
  • Carefully took apart the Naomi 2 to clean the fans. I DID NOT remove the case fan or the fans on the dual CPUs. Only used can of air to clean them out.
  • No caps were bumped, broken, or moved in any way - Super careful.
  • Put the unit back together and everything booted as it normally would.
  • After the game is loaded and the hardware reboots, the Naomi 2 boots the game as it normally would.
  • Only now, after the game has completely loaded (you can tell by the initialization splash screen for each individual game), right before the game's attract sequence or title would normally appear a message saying "Entering Test Mode" will come up and forces me into the Test menu.
  • When in the Test menu the Test and Service buttons do not work - so I cannot exit the test menu at all.
  • The Naomi 2 boots fine without the Net Dimm, but I can't enter the Test menu from the Naomi 2 splash screen.
Additional Information:
  • I do not have any actual Naomi carts to try currently, but I have a few on the way that should be here sometime next week.
  • In doing some research online I read that many of the hardware issues are due to a leaking Super Capacitor, and that the hardware can run just fine without it. In fact, most threads recommended removing it.
    • I (cleanly) removed it only AFTER the Test Menu issue happened as a last resort - not before.
    • Removed the cap, and there was a tiny bit of acid leak - used a small amount of water/baking soda solution with a cotton swab to remove the very tiny bit of acid residue that was around where the cap was. This very small leak did not affect any other parts of the board.
    • There are no broken traces from what I can tell.
    • Naomi 2 still boots 100% fine without the Super Capacitor, but runs into the same issue as above - boots the game, then forces Test mode.
  • I also replaced the 2032 lithium battery, which did nothing.
  • There are no other hardware errors, no error message comes up on the Naomi when booting a game.
  • I doubt it's an issue with the output board as all other outs (JVS data cable, power, vga, sound, etc. all work fine).
  • All dip switches are set to OFF.
  • If there were external hardware errors, like a bad IO, PSU, etc, to my knowledge the Naomi would not boot - let alone go through the entire boot and load cycle to begin the game.
Any help? Thoughts? Thanks peeps.
 
Last edited:

awbacon

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I mean without having ANY idea because I've never heard of this logically it sounds like somehow those buttons are shorted to ground and always "on"...so as soon as POST will allow entering into the test menu...it happens

How would you have caused that? Zero idea. My ONLY thought is removing / reinserting the Dimm board...maybe a pin was pushed and grounded out and SOMEHOW that triggers test?

LOOOOOONG shot
 
Last edited:

Evan

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I mean without having ANY idea because I've never heard of this logically it sounds like somehow those buttons are shorted to ground and always "on"...so as soon as POST will allow entering into the test menu...it happens

How would you have caused that? Zero idea. My ONLY thought is removing / reinserting the Dimm board...maybe a pin was pushed and grounded out and SOMEHOW that triggers test?

LOOOOOONG shot
Yeah my guess would be the same. Maybe its a similar issue to some atomiswaves where they have diodes fail making certain points be always grounded?
 

yagamikun

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I mean without having ANY idea because I've never heard of this logically it sounds like somehow those buttons are shorted to ground and always "on"...so as soon as POST will allow entering into the test menu...it happens

How would you have caused that? Zero idea. My ONLY thought is removing / reinserting the Dimm board...maybe a pin was pushed and grounded out and SOMEHOW that triggers test?

LOOOOOONG shot

Thanks, AW and Evan. I'll take a look at the connector pins on the DIMM and MOBO and see if there is anything amiss. My buddy also mentioned it sounds like something is making the Naomi think the Test button is being held down, and that was my suspicion as well. I'll tinker some more with it this morning and report back.

Also, thanks for confirming I'm not crazy. I've never, ever, seen anything like this. :)

EDIT: No dice - all connections are in order and I even cleaned all contacts with Deoxit to make sure it's all good. 🤬
 
Last edited:

awbacon

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Thanks, AW and Evan. I'll take a look at the connector pins on the DIMM and MOBO and see if there is anything amiss. My buddy also mentioned it sounds like something is making the Naomi think the Test button is being held down, and that was my suspicion as well. I'll tinker some more with it this morning and report back.

Also, thanks for confirming I'm not crazy. I've never, ever, seen anything like this. :)

EDIT: No dice - all connections are in order and I even cleaned all contacts with Deoxit to make sure it's all good. 🤬
do you have a multimeter. I'd check the areas around the test buttons. There should be no continuity between ground and signal unless the button is depressed.

With it powered on check continuity between a ground leg on the button and the signal leg. If you get a beep that means its grounded out and active. If you dont....well I am out of ideas! You can check with it powered off too
 

awbacon

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I'd also do some really simple stuff like reseat the bios chip. Hell maybe even try a different chip entirely. Since this is such a one off issue I'd really start simple with stuff like that. Rule it out at least before you take a deep dive
 

yagamikun

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I'd also do some really simple stuff like reseat the bios chip. Hell maybe even try a different chip entirely. Since this is such a one off issue I'd really start simple with stuff like that. Rule it out at least before you take a deep dive.

Thanks! I'll mess with the bios and see if that does the trick.

I did try the multimeter, but I'm still learning some of the technical side of this stuff so I very well could have been testing the wrong points. Here's some pics of what I've done and the multimeter I'm using. The setting on the multimeter is what I use to check the voltages in my cabs, so I assume that's fine here or should I be using a different setting entirely?

I tested both the front and back of the buttons' legs in different configurations and every time it came out 0. I got a tiny spike when I pressed a button once, but I think it was a fluke.

EDIT: Tried to reseat the bios and same result. I'll have to source another bios - I think I can just use a Multi from ebay?


20210429_111629.jpg

20210429_111635.jpg20210429_111653.jpg
 
Last edited:

awbacon

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Thanks! I'll mess with the bios and see if that does the trick.

I did try the multimeter, but I'm still learning some of the technical side of this stuff so I very well could have been testing the wrong points. Here's some pics of what I've done and the multimeter I'm using. The setting on the multimeter is what I use to check the voltages in my cabs, so I assume that's fine here or should I be using a different setting entirely?

I tested both the front and back of the buttons' legs in different configurations and every time it came out 0. I got a tiny spike when I pressed a button once, but I think it was a fluke.

EDIT: Tried to reseat the bios and same result. I'll have to source another bios - I think I can just use a Multi from ebay?


View attachment 49151

View attachment 49152View attachment 49153
You need to use continuity mode. Normally thats a diode or "sound wave/speaker" looking icon...but I don't see that on yours?

(see symbols here : https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter/continuity)

Perhaps that multimeter doesn't have a continuity mode? I've never seen one that doesn't but?

(Yeah I looked the manual up. That multimeter doesn't have continuity mode. Weird!)

I'd buy a new one and do this...

To make sure you are testing the right contacts in continuity mode, just pick any GROUND point and pop a probe on it. Check the legs on the buttons and listen for the beep. That will tell you what ground is. You should also be able to just use the USB metal housing as ground as that should be grounded too.

Once you've located the ground pin on the buttons (probe all connections. Whatever doesn't have continuity to ground is the signal pin) check continuity between the GROUND ON THE BUTTON and the SIGNAL PIN ON THE BUTTON.

If you get a beep it's shorted to ground.

If you DONT get a beep your problem is elsewhere (button is not shorted to ground)
 

yagamikun

,
20 Year Member
Joined
Oct 10, 2000
Posts
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You need to use continuity mode. Normally thats a diode or "sound wave/speaker" looking icon...but I don't see that on yours?

(see symbols here : https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter/continuity)

Perhaps that multimeter doesn't have a continuity mode? I've never seen one that doesn't but?

(Yeah I looked the manual up. That multimeter doesn't have continuity mode. Weird!)

I'd buy a new one and do this...

To make sure you are testing the right contacts in continuity mode, just pick any GROUND point and pop a probe on it. Check the legs on the buttons and listen for the beep. That will tell you what ground is. You should also be able to just use the USB metal housing as ground as that should be grounded too.

Once you've located the ground pin on the buttons (probe all connections. Whatever doesn't have continuity to ground is the signal pin) check continuity between the GROUND ON THE BUTTON and the SIGNAL PIN ON THE BUTTON.

If you get a beep it's shorted to ground.

If you DONT get a beep your problem is elsewhere (button is not shorted to ground)
Cool, thanks! I'll run to Microcenter this weekend and grab a new meter. Super helpful!
 

lachlan

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If it's not grounded all the way back to the pin origins (likely an IC) then it might be internal... These damn boards are so fragile, I had a cpu die literally seperate from it's substrate just being shipped.
 

awbacon

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Cool, thanks! I'll run to Microcenter this weekend and grab a new meter. Super helpful!
pro tip....look up whatever you see at Micro Center on Amazon. They price match. I save money doing that basically every time I go in
 

awbacon

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If it's not grounded all the way back to the pin origins (likely an IC) then it might be internal... These damn boards are so fragile, I had a cpu die literally seperate from it's substrate just being shipped.
typical Sega. Hikaru grenades itself if a strong breeze hits it
 

awbacon

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Must be all the years of 24/7 use and lack of airflow. I bet they cook themselves.
they forgot to tin the pads on the pcb itself...they just tinned the processors

so the processors LOVE to break free from the motherboard, requiring a full reball....which is shit I can't do lolol

Another Sega design flaw
 
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