Blast city & Sega Naomi in 31kHz VGA?

[Rocco]

Hello

2 days ago I tried and finally installed my Naomi 2 to my Blast city cabinet.

I used a Capcom Converter to connect the Naomi JVS with the Blast city JAMMA.


But the monitor only worked fine setting up the Dip Switch 1 to ON... What means for working in 15 kHz instead of 31 VGA.


My question is, can be connected in 31kHz VGA mode?
In theory, Blast city monitors are ready for 15,24 and 31 true?

[NeoBliss]

Yes. You can use 31 kHz with a Blast City/Naomi setup.

You'll only need the Capcom I/O for the controls if you have a 001 loom. Hook up the vga cable from the chassis directly to the Naomi motherboard. Then set the dip settings in the Blast City for 31 kHz (if you have a manual sync chassis) and do the same for the Naomi Motherboard.

If you don't have a 001 loom then you'll use the Capcom I/O for sound and controls but still use the vga cable from the chassis to connect to the motherboard.

Hope that helps.

[nem]

Then set the dip settings in the Blast City for 31 kHz (if you have a manual sync chassis) and do the same for the Naomi Motherboard.

There's also a separate dip switch on the Blast to change the input from the 15 PIN AMP connector to the D-SUB one.

[Rocco]

DSC_0112.JPG

I just took a look behind the chassis monitor of my Blast city.

There are 2 stickers on it.

One from Toshiba and other what says is MS-2930-SE.

In my little visual inspection I didn't see any VGA plug around, could you tell me where should be looking located? ( if really have... )

[Rocco]

Other

[Rocco]

DSC_0114.JPG

[Rocco]

Again

[Rocco]

I finally found it!

[kuze]

[Rocco]

And finally found as well where the manual synch dip Switches are

And the Naomi now can be used perfectly with 15 and 31 kHz

Getting better day a day!

[zumbito]

Then set the dip settings in the Blast City for 31 kHz (if you have a manual sync chassis) and do the same for the Naomi Motherboard.

There's also a separate dip switch on the Blast to change the input from the 15 PIN AMP connector to the D-SUB one.

Does this mean that the front switches are not enough to change from 15 to 31? Also need to change the back one?

[nem]

No, that switch is on the front as well. On the front you can choose whether the signal is 15khz, 24khz or 31khz, and which input it is, 15 pin AMP or D-SUB.

[hindered]

Sorry to necro this topic but I'm having the same problem. Blast city manual sync with Naomi 1 motherboard. 15khz works fine. Switch monitor and motherboard to 31khz and I get failed sync (screen warped hardcore) and I can't adjust it out. Most of my experience is with older games and it looks like a horizontal sync issue that could be adjusted out, but I don't think these monitors have a pot for that, right?

[hindered]

Ok, I did some trouble shooting to see if the problem was obviously on the Naomi or the monitor (ms-2930-s). No dice. Here's what I did:

Hooked up neo geo motherboard. Monitor on 15khz. Dsub off. Everything works as expected.
Same setup, dsub on. Dim picture as expected - confirmed: dsub dip works.
Neo geo, monitor at 31khz, dsub off. No picture (don't remember if it was scrambled, or black). Confirmed: Flipping dip 2 changes behavior of monitor.

Naomi, 15k, monitor 15k, ran video through sega jvs I/o, dsub off. Everything works.
Naomi, 15k, monitor 15k, ran video to monitor directly, dsub on. Everything works. Confirmed: Naomi can output 15k through I/o and through direct connection (different cables). Cables probably ok.

Naomi 15k, monitor 31k, no sync as expected.
Naomi 31k, monitor 15k, no sync as expected.

Naomi 31k, monitor 31k, still no sync through either the I/o or direct. Picture is super scrambled. The adjustments on the front of the cab do nothing helpful.

For funsies I put the monitor in 24k with the Naomi at 31k. the picture was more legible than when the monitor was at 31k but bad squeal and still no good. Confirmed: monitor can enter three different modes. All dip switches seem to work.

Does anyone have any ideas? Does this sound like an adjustment one of the pots on the main chassis can help? My gut is telling me no... Hoping one of the experts can guide me.