Nanao MS-2930-S 31khz Display issue with Naomi
Posted: March 4th, 2017, 5:36 pm
Hi all,
I posted this information in another thread (http://forum.arcadeotaku.com/viewtopic. ... ca#p469590), but in hindsight a: I shouldn't have necro'd/hijacked an old thread, b: I've done enough troubleshooting that it seems clear to me that it's a monitor issue at this point. So, I decided to start a new thread in the Monitor area.
I have a Blast City with a Nanao MS-2390-S manual tri-sync monitor. I also have a handful of game boards (Neo Geo MV-1, Sega ST-V, Naomi) to test with the board. The short version is that 15khz works properly, but 31khz mode does not work. Since the boards and cabinet were all new to me, I wasn't sure 100% that the game boards themselves were good, so I suspected them along with the monitor (which needs a cap kit).
Here's some troubleshooting I did to narrow it down
-----------
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.
-------------------------
At this point, I rememberd that I had an old low resolution LCD monitor in the basement, so I went and hooked it up to the Naomi in 31khz mode -- success! Confirmed: The Naomi can properly output 31khz VGA.
This means that the problem has to lie with the nanao monitor, right? I actually got around to taking pictures of the display issue as well. I really feel that it's something that should be adjustable via pot but the ones on the front don't help me, and from looking at the manual, none of the ones on the chassis seem likely either (though there are some pots in the manual that aren't labelled, maybe one of those?).
I posted this information in another thread (http://forum.arcadeotaku.com/viewtopic. ... ca#p469590), but in hindsight a: I shouldn't have necro'd/hijacked an old thread, b: I've done enough troubleshooting that it seems clear to me that it's a monitor issue at this point. So, I decided to start a new thread in the Monitor area.
I have a Blast City with a Nanao MS-2390-S manual tri-sync monitor. I also have a handful of game boards (Neo Geo MV-1, Sega ST-V, Naomi) to test with the board. The short version is that 15khz works properly, but 31khz mode does not work. Since the boards and cabinet were all new to me, I wasn't sure 100% that the game boards themselves were good, so I suspected them along with the monitor (which needs a cap kit).
Here's some troubleshooting I did to narrow it down
-----------
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.
-------------------------
At this point, I rememberd that I had an old low resolution LCD monitor in the basement, so I went and hooked it up to the Naomi in 31khz mode -- success! Confirmed: The Naomi can properly output 31khz VGA.
This means that the problem has to lie with the nanao monitor, right? I actually got around to taking pictures of the display issue as well. I really feel that it's something that should be adjustable via pot but the ones on the front don't help me, and from looking at the manual, none of the ones on the chassis seem likely either (though there are some pots in the manual that aren't labelled, maybe one of those?).