Is this Naomi PCB dead or am I doing something wrong?

[leonk]

I recently purchased a Naomi 2 setup to add into my Sega New Astro City, which is currently running MAME using a JPAC ..

Because of the PC, the onboard power supply is disabled, but I do use the JAMMA harness with the JPAC to feed the MS9-29A 15khz video and all joysticks/buttons connect via JAMMA.

Here's how I connected the Naomi 2:

- Naomi (SUN) PSU with 2 power connectors to main board
- USB cable from main board to Sega IO rev B
- VGA cable from main board to Sega IO
- Sega IO gets its power from the PSU using little 6 pin connector
- Sega IO plugged into JAMMA harness in NAC
- RCA plugs go to small external amp driving speakers
- Monitor + Marquee lights + AMP + PSU all connect to power bar inside NAC
- jumper set to 15khz

The issue I'm having is no video / no audio. I've confirmed using a multimeter 5.1V, 3.4V and 11.95V. I tested all test points on Naomi 2 and voltage set correctly. The 2 lights on main board are on, and 3 fans are spinning. All I get is black screen.

I can hear a relay click on the IO board when power is on/off.

Am I missing something? Does the JAMMA harness need power from the NAC PSU, or getting power from same PSU as Naomi 2 good enough? What about sync? Does the SEGA IO rev B provide the correct sync for an MS9-29A?

As a last resort, I flipped the dipp switch to 31khz, and tried plugging to a PC VGA port as well as my HDTV.. both said no signal.

The last thing I'd like to add.. the board came to me with the USB port 1/2 ripped off! (damaged in transit -- thanks USPS!) I desoldered/soldered it back on using my rework station and confirmed all connections are good. Could it be that something else broke inside causing black video/no sync?

Or do I need to do something to the video output from a Sega IO rev B before feeding it into an MS9-29A?

 

[300wins]

First thing you should do is try to test your Naomi 2 on a different cab and see if you get the same results. Best to run it on a JVS cab if possible.

If it doesn't work on a different cab, then I suggest you look at replacing the filter board. Lots of times, these go out. The filter board is the whole front face (in case you didn't know).

See if your bios chip or any other chip on the system came loose. And lastly, make sure the connection between the game and mobo is good with no bent pins and such.

I recently purchased a Naomi 2 setup to add into my Sega New Astro City, which is currently running MAME using a JPAC ..

Because of the PC, the onboard power supply is disabled, but I do use the JAMMA harness with the JPAC to feed the MS9-29A 15khz video and all joysticks/buttons connect via JAMMA.

Here's how I connected the Naomi 2:

- Naomi (SUN) PSU with 2 power connectors to main board
- USB cable from main board to Sega IO rev B
- VGA cable from main board to Sega IO
- Sega IO gets its power from the PSU using little 6 pin connector
- Sega IO plugged into JAMMA harness in NAC
- RCA plugs go to small external amp driving speakers
- Monitor + Marquee lights + AMP + PSU all connect to power bar inside NAC
- jumper set to 15khz

The issue I'm having is no video / no audio. I've confirmed using a multimeter 5.1V, 3.4V and 11.95V. I tested all test points on Naomi 2 and voltage set correctly. The 2 lights on main board are on, and 3 fans are spinning. All I get is black screen.

I can hear a relay click on the IO board when power is on/off.

Am I missing something? Does the JAMMA harness need power from the NAC PSU, or getting power from same PSU as Naomi 2 good enough? What about sync? Does the SEGA IO rev B provide the correct sync for an MS9-29A?

As a last resort, I flipped the dipp switch to 31khz, and tried plugging to a PC VGA port as well as my HDTV.. both said no signal.

The last thing I'd like to add.. the board came to me with the USB port 1/2 ripped off! (damaged in transit -- thanks USPS!) I desoldered/soldered it back on using my rework station and confirmed all connections are good. Could it be that something else broke inside causing black video/no sync?

Or do I need to do something to the video output from a Sega IO rev B before feeding it into an MS9-29A?

 

[Tacitus]

If u have an LCD monitor or VGA monitor, hook it directly up to the VGA port on the NAOMI. It will absolutely tell you if it's a video issue or a power/io issue.
Saves your havin to move cabs and it eliminates one possibility immediately.

 

[leonk]

Thanks for the great tips. I managed to find another Naomi 2 board and it works! It seems Naomi can boot with no io board attached (it will give you error later) and easily connected to HDTV using VGA cable + 31khz mode.

Arggg can't believe USPS killed the Naomi 2 board.

 

[Tacitus]

Thanks for the great tips. I managed to find another Naomi 2 board and it works! It seems Naomi can boot with no io board attached (it will give you error later) and easily connected to HDTV using VGA cable + 31khz mode.

Arggg can't believe USPS killed the Naomi 2 board.

You'll get the "game is not compatible" message, I believe..

Keep plugging away, it may be a voltage issue.... those things are relatively hard to kill!