Naomi 1 w/ Net DIMM 4.01 Setup

OldFoo · Post by **OldFoo** » Wed Aug 10, 2011 12:05 am

Hi all. So I purchased a Net Dimm 4.01 with BIOS H from a member here and am just getting a black screen when I try to start system. I have tried both the new BIOS and my previous E version, moved the dip switches and jumpers around, took the DIMM out of black case to make sure connections were tight and still can't get past black screen. Anyone have any insight?

It is a Naomi 1 MB with Capcom I/O, Net Dimm 4.01 and H BIOS. Monitor is 15k and I have dipswitch 1 up with other 3 down. Jumpers 1 and 2 are left (on I think for networking), 3 is right, then 4, 5 left, 6 right. System works fine w/ old BIOS and MvC2 cart, but no luck even getting to splash screen with Dimm.

OldFoo · Post by **OldFoo** » Wed Aug 10, 2011 8:56 am

First check your power supply status. The DIMM draws more power than a standard cart does. Especially make sure the 5V is around 5.1.

OldFoo · Post by **OldFoo** » Thu Aug 11, 2011 12:03 am

OK, so I bought a multi meter and adjusted voltage to 5.1v. I then plugged in the Dimm and re-measured voltage and it dropped to 0.25. I tried turning dial to increase voltage, but couldn't get it any higher than 0.27. Any thoughts on what could cause this or how to fix it? Thanks again.

OldFoo · Post by **OldFoo** » Thu Aug 11, 2011 5:02 am

NetDIMMs in a Naomi sometimes take a few minutes before the splash screen is displayed. I thought mine was broken too, until I found out about that oddity.

OldFoo · Post by **OldFoo** » Thu Aug 11, 2011 7:51 am

Check for any broken/bent pins on DIMM/Naomi connections.. A voltage drop to 0.25v is abnormal.

OldFoo · Post by **OldFoo** » Thu Aug 11, 2011 5:12 pm

Is it possible the dimm needs a seperate power supply despite the fact that theres no gd-rom? If so, how would it be connected since the dimm has no input for a power cable? Should I buy a cable splitter for the second power supply and then just run that into the 6-prong molex on the naomi mobo for extra juice?

I examined the pins closely and everything looks fine and I've left the machine on for an hour and still got black screen. I'm honestly new to all this and can't think of what else to try.

OldFoo · Post by **OldFoo** » Thu Aug 11, 2011 11:00 pm

dtheman2222 wrote:Is it possible the dimm needs a seperate power supply despite the fact that theres no gd-rom? If so, how would it be connected since the dimm has no input for a power cable? Should I buy a cable splitter for the second power supply and then just run that into the 6-prong molex on the naomi mobo for extra juice?.

Ehh.. please don't

You will kill the Naomi if you do.

What PSU are you using?

OldFoo · Post by **OldFoo** » Thu Aug 11, 2011 11:47 pm

Heh. Good thing I asked. The one in the cab is a Uni-San which has a 9-prong and 3-prong molex and I have a second PSU I tested with (same drop to 0.25v) that is a Pacific Electric with two 9-prong and a 3-prong and says +3.3v/+5v, but no mention of 12v.

Everything I've read seems to indicate my problem is power, but I can't figure out how I'd hook up the second PSU to the Naomi mobo to power the dimm if I don't have a GD-Rom for the input. Maybe I'm still totally off base and powers not the issue?

OldFoo · Post by **OldFoo** » Fri Aug 12, 2011 7:22 am

No, there is no need for a second power supply to run a Naomi with a net DIMM. It is common to use an additional power supply when powering the Naomi through the Capcom I/O.

Please provide more detail on how you hooked up the system. If the PSU is currently powering the Capcom I/O, and the Capcom I/O in turn powers the Naomi, try taking the I/O out of that loop, and power the Naomi directly from a PSU.

Also, check the pinout of the output of the PSU. I do not have any experience with the PSU's you mention. Make sure the PSU outputs enough power (minimal output: 3.3V 12A, 5V 10A, 12V 2A.) and has the correct pinout.

OldFoo · Post by **OldFoo** » Fri Aug 12, 2011 1:39 pm

Cageman wrote:No, there is no need for a second power supply to run a Naomi with a net DIMM. It is common to use an additional power supply when powering the Naomi through the Capcom I/O.

Ok, I apologize but I'm lost.

The setup is as follows.

PSU to Jamma harness to Capcom I/O to Naomi MoBo via top output on Capcom to 8-prong molex on MoBo

Monitor to Jamma to Capcom I/O to Naomi MoBo via VGA

Controls to Jamma to Capcom to Naomi via USB

Audio from speakers to Jamma to Capcom to Naomi via red/white

What I don't get is you said there is no need for a second PSU, but then that it's common to use a second PSU w/ a Capcom I/O. Since I have the PSU going to the Capcom I/O and then to the Mobo as you described, do I need a second PSU or no? How would I bypass the Capcom I/O to hook up the PSU directly to Mobo since the inputs are different (9-molex out of PSU, 8-molex and 6-molex input on MoBo)? Also, doesn't the Capcom convert the current to power the Naomi? Do I buy the splitting cable and then run that direct from second PSU to Mobo and then leave the original PSU to power the Capcom I/O?

I will check the pinout and PSU as you suggested and really apologize that I'm being a huge pain, just really desperate to get this up and running.