NAOMI GD-ROM Help

[Madgear]

Question for y'all....

I'm new to getting Naomi2 setup- and I am getting an ERROR 25 message (Can not access the GD-ROM Drive)--so I want to check my understanding.

I have the SEGA/CAPCOM IO board receiving the JAMMA harness and Kick Harness for extra buttons, and on the opposite end, the standard connectors for the Naomi Board (which with a Naomi 1 game, works just fine.) In this particular case of error, I have the Naomi 2 DIMM cartridge, and security key in the Naomi 1 board, and the SCSI cable connecting the GD-ROM to the Naomi 2 DIMM cartridge. I see an additional 6-pin connector on the GD-ROM but read somewhere that since I'm using JAMMA for power, that I don't need anything there.

Either way, still getting this error. Any suggestions? Photo displayed if it helps!

naomi.jpeg

[jimmerd]

Are you saying it all worked okay with the GDROM and another DIMM board, but you swapped it out to a new DIMM board taken from a Naomi 2 and at that point the GDROM stopped working?

Or was it that you had a Cartridge based Naomi 1 game, but the GDROM has never worked?

It goes without saying you an not play a Naomi 2 game on Naomi 1 motherboard irrespective of the DIMM board model, but playing a Naomi 1 game should be okay assuming the DIMM board is compatible/working.

If you have never had the GDROM spinning then from what I remember ( others please correct me if wrong)

The GD-ROM needs it's own power, the Capcom IO won't put out enough voltage for the DIMM cartridge and GDROM together at the same time.

For example, you can use an regular ATX PSU with an adapter.

https://www.ebay.co.uk/itm/173872868017

[Madgear]

Are you saying it all worked okay with the GDROM and another DIMM board, but you swapped it out to a new DIMM board taken from a Naomi 2 and at that point the GDROM stopped working?

Or was it that you had a Cartridge based Naomi 1 game, but the GDROM has never worked?

It goes without saying you an not play a Naomi 2 game on Naomi 1 motherboard irrespective of the DIMM board model, but playing a Naomi 1 game should be okay assuming the DIMM board is compatible/working.

If you have never had the GDROM spinning then from what I remember ( others please correct me if wrong)

The GD-ROM needs it's own power, the Capcom IO won't put out enough voltage for the DIMM cartridge and GDROM together at the same time.

For example, you can use an regular ATX PSU with an adapter.

https://www.ebay.co.uk/itm/173872868017

Thanks for this reply! I have played a Naomi 1 cartridge no problem, but nothing with the GD-ROM seems to work...and it seems like it's because of what you said!

"The GD-ROM needs its own power, the Capcom IO won't put out enough voltage for the DIMM cartridge and GDROM together at the same time."

I dunno know why I thought the Capcom I/O was enough power! Thanks man! I'll grab a PSU--

Naomi 2 is a bit much of a setup! I'm really enjoying the ease of the CPS2 board in comparison LOL

[nem]

There is no problem running discs with the Capcom IO. The GDROM drive needs +5V and +12V, both of these come from your PSU. It's only +3.3V that comes from the Capcom IO, and if working correctly it should supply enough amps for a Naomi with a regular DIMM board.

@Madgear, you're missing the power harness for your GDROM drive.

Here's one on eBay:

https://www.ebay.com/itm/183167566766

[Madgear]

There is no problem running discs with the Capcom IO. The GDROM drive needs +5V and +12V, both of these come from your PSU. It's only +3.3V that comes from the Capcom IO, and if working correctly it should supply enough amps for a Naomi with a regular DIMM board.

@Madgear, you're missing the power harness for your GDROM drive.

Here's one on eBay:

https://www.ebay.com/itm/183167566766

Whoa! Thank you @nem ! So, I grab this, connect the GD ROM 6 pin connector and the other end to the I/O board and I'm good to go? Buying one cable is def a solution I can get with

[nem]

Yes, you're good to go with that one cable.

[Madgear]

Yes, you're good to go with that one cable.

Awesome!

[jimmerd]

Whoa! Thank you @nem ! So, I grab this, connect the GD ROM 6 pin connector and the other end to the I/O board and I'm good to go? Buying one cable is def a solution I can get with

I assume the power cable from the GDROM can't be connected to the Naomi motherboard? (eg to the left of the Capcom IO) nor the Capcom IO as that's already in use and therefore allways needs to go directly to a PSU to obtain the required voltages? The original Sun PSU's had the correct socket and maybe the psu in your cabinet, otherwise in the past I used an adapter for a regular PC ATX supply.

It's been a while since I had a Naomi thru a Capcom IO but I remember it looking like a science laboratory as in the photo

[nem]

The power cable I linked to sits in between the Naomi motherboard and the IO. It's a pass through.

[Madgear]

Whoa! Thank you @nem ! So, I grab this, connect the GD ROM 6 pin connector and the other end to the I/O board and I'm good to go? Buying one cable is def a solution I can get with

I assume the power cable from the GDROM can't be connected to the Naomi motherboard? (eg to the left of the Capcom IO) nor the Capcom IO as that's already in use and therefore allways needs to go directly to a PSU to obtain the required voltages? The original Sun PSU's had the correct socket and maybe the psu in your cabinet, otherwise in the past I used an adapter for a regular PC ATX supply.

It's been a while since I had a Naomi thru a Capcom IO but I remember it looking like a science laboratory as in the photo

ABSOLUTELY looks like a science lab- it baffles me how this was ever a standard, I feel for arcade operators back in the day

and @nem, that's good to know- I picked it up! When it arrives I'll definitely update the thread before testing--juuuust to make sure I don't destroy any parts of my Naomi setup lol

[Madgear]

Success! Thanks for that cable recommendation @nem ! Just picked up some mounting brackets and getting this set up!

[nem]

Perfect

[Madgear]

EDIT- re: printing—found a spot! Thanks again

[Madgear]

Update!

Again, thanks @nem for all the help! I’ve got this new 3d printed bracket and Naomi set up organized way way wayyyyy nicer than the original photo!

Bad news: After a few operable sessions, my GD-ROM is giving me error 25 AGAIN. Despite working a few times with the new setup and power, I’m thinking maybe its the disc? So, picked up a cheap find and once it arrives, I’ll see if its the game, or actually the GD rom again.

But these mounting feet for the I/O board? Amazing. Thank you!

IMG_5577.jpeg

IMG_5576.jpeg

[nem]

It's not the disc.

Have you measured the voltages? What do they show?

[Madgear]

Ah, good to know!

Im going to be very honest here: absolute noob. Lol Ive collected for a while, but every issue is a new experience to learn lol

I have a multimeter, and have used it once. LOL Let me measure the voltage and let you know! I wouldnt have thought to do that lol

[nem]

Set your multimeter to DC voltage and put your black meter lead on a ground point and the red meter lead on the voltage that you want to measure. Ideally you want to measure as close to the system as you can.

On a Naomi I would measure from the filter board power connectors:

naomi_measuring_voltage.jpg

Brown wire is +3.3V
Yellow +5V
Red +12V

[Madgear]

Excellent reference @nem Thank you!

[Madgear]

Set your multimeter to DC voltage and put your black meter lead on a ground point and the red meter lead on the voltage that you want to measure. Ideally you want to measure as close to the system as you can.

On a Naomi I would measure from the filter board power connectors:


naomi_measuring_voltage.jpg


Brown wire is +3.3V
Yellow +5V
Red +12V

Thanks again for the instructions @nem ! I picked up a new multimeter, and my results were:
Red: 11.6
Yellow- 0
Brown- 0

I have a feeling that these zeroes are an obvious issue. Do I need to get a new loom, you think?

[nem]

I'm sure the loom is fine. You're measuring wrong somehow. If there was no power there, the system wouldn't boot at all.

What's happening on screen when you're measuring? Is the system sitting at Error 25?