Nanao MS8-26SU -- No Vertical Hold... :( --->FIXED!!!

[gokun]

Hi everyone; first let me just say I'm a noob so be gentle with me.  
As near I can tell from the ID sites, etc. I have the Nanao ms8-26SU(or U) chasis with the Mitsubishi tube on it...it is from an original Sega fighting vipers cab in which it still lives.
The basic problem is that I cannot seem to lock the vertical hold at all.
The setup is that the cab has been converted to jamma and now houses a Naomi which I wanted to run in the cab for various reasons. So everything works fine on the naomi side(tested and re-tested) and the Naomi and the monitor are both set to 15K. Oh! And the monitor is connected directly to the Naomi's vga output cable(I made a plug-checked and re-checked that too) not the jamma harness(just using the harness for the controls).
Currently I have a composite signal going into the monitor's h/v line: I get the slow roll upwards; won't lock in.
With just the V into the h/v: I get the exact same thing.
With just the H into the h/v: neither horizontal nor vertical will totally lock; slow upward roll coupled with slow leftwards roll.
With H into h on the monitor and v into v on the monitor: same thing again;slow upwards roll.
This one doesn't have the remote board, all the knobs are on the front, and as far as I can tell they are all working(but I dunno how to test properly to be sure honestly-but they seem to be doing what they are supposed to for the most part). The vertical hold knob feels very sensitive in the area where you would think it would lock...it's almost like it slips or something.
Anyways, what else...I checked all the wiring and that looks good. Re-checked the sync and ground lines to be sure...they look ok. And the monitor was working before in 24K mode with fighting vipers.
Basically the story goes: While converting the wiring to jamma harness I inadvertantly wired the video backwards...obviously the picture then looked all garbeld...so me being a genius and all I go and turn the knobs trying to get a picture then realize I have it wired wrong. doh! so rewire it the right way this time and turn it on and everything looks great except that, of course, the slow vertical roll. And I suppose it is possible that I could have touched something wrong when switching the plug to 15k on the monitor but I did not notice doing so at the time and nothing seems out of place as far as I can tell...
Anyway, I really have no idea where to go next or what to do here, and was hoping someone might be able to shed some light on this for me or send me in the right direction...I'm not unfamiliar with a soldering iron, etc. so if it's not something too major I might could manage it. Thanks in advance....oh! and I do have a video of what it is doing if you really need to see it; so just let me know if so and I'll upload it somewhere.

[bluevolume]

My first suggestion is to include paragraphs in a post that long.  It makes it much easier to parse a lot of detail.

[grantspain]

someone on another forum is having this same problem but with a 50" rptv,i personally think that to get the correct frequency you need to have a jamma interface i/o card.
today i am gonna check a naomi on a 15/25 monitor so i will post the result when known

[gokun]

Well, I have two of the Sega I/O revision a cards and both work fine, but when using them I get the same exact problem...go figure.

[gokun]

My first suggestion is to include paragraphs in a post that long.  It makes it much easier to parse a lot of detail.

lol! Yeah, sorry about that.

[Ken Layton]

Contact Joey at www.jomac.net.au/mon.htm

He is in Australia and is a Nanao expert. Remember, support, parts, and manuals for Nanao monitors is non-existant in the USA.

[grantspain]

i connected a naomi via jamma i/o to a ms8 today with no issue's,the only difference between my set up and yours is the fact you have a direct connection from the naomi to the monitor whereas mine connects via the i/o card

[gokun]

Well, that's what I was afraid of...according to Joey from the jomac website, if the pots are good and my connections are good and the signal from the board is good(I'm paraphrasing here obviously), then it's most likely "a faulty sync module , these are not available and only some can be repaired successfully." Which is bad news for me I suppose....still, I can't help wonder how it happened so suddenly...but I digress...
assuming for now that it could still possibly be something else, I guess the next likely candidate would be the pot...I only say that because it really does act like it's literally slipping...it even favors one side more than the other...for example, if I turn the pot just far enough to make it scroll slowly down instead, it will eventually stop, then roll up again.
However, if I leave it scrolling up it always scrolls up.And it always seems to roll up at about the same pace unless I muck with the pot again...
if I were to put a meter to the pot, would I be able to see from the readout if the pot was actually slipping in that spot? I only obsess about the pot because, as far as I am aware, they had never been moved for years until I touched them so it's not inconceivable that one or more could have broken or gotten messed up somehow. Honestly, I am doubtful that it would be something that easy, but it would be nice...otherwise I guess I'm looking at replacing the monitor or sending to AU to have it fixed(if possible).
At any rate, let me know if I'm being silly about the pot. And thanks again for the input!

[grantspain]

before you start sending for repairs first reinstall the 24khz game and set the monitor plug to 24khz just to prove that works

[gokun]

check; will let you know how that turns out. Should be able to do it tonight or tomorrow.

[grantspain]

if that works i seriously doubt its a monitor sinc issue(joey is the man on these monitor though)
i know the 15khz output from naomi is not a perfect 15khz
this from a chap over at the killercabs forum
"i think the issue is down to the fact that Naomi at 15K isn't progressive.

It is overscaned, interlaced to get a high resolution display at 15K, a few TVs/scan convertors have issues with the Naomi at 15K"

but i do know a naomi works on my ms8 via sega i/o board,i did not try connecting directly from the vga to the monitor

[northerngames]

I just went through the same thing with mine on your monitor input use the R,G,B,H,GRD only and have the H and V going to it connected do not have the V hooked to anything from the monitor.

I had spent hours and these monitors will not sync when seperated or anything hooked to V chassis wise it just don't work 

this would have nothing to do with your issue but if your screen is to wide and your H. size does no justice there is a orange wire near the PSU area that is on a single wire harness and it can be swapped to the next pin over to make everything fit into the screen like it should if it is not set that way already that is the wide or thin selection pin.

[gokun]

OK, being the obsessive compulsive guy I am I simply couldn't stand waiting to test, so I went ahead and rewired the whole cab back to original spec(within reason-didn't reconnect controls, lights, etc because I didn't need them for the test)...anyhoo....
With fighting vipers back in and the monitor set back to high I get....perfect picture. (?)
Locks in relatively easily(took me maybe 3 seconds) and stays there(let it run for 30minutes to be sure it wouldn't move-it didn't)....
so now I'm really REALLY confused....I suppose it's possible that just the 15k stuff could be bad, but I find that odd. At least I can finally let go of my bad pot theory though(the pot also did not slip when I tested it with the meter)...in the meantime though, where do I go from here? I mean, it's odd that it would work on a virtually identical setup but not mine....I do have another naomi though so I guess I could try that one instead just to say I've tried everything I can think of.
Also, I get the issue with or without the I/O card...tried it both ways...figured maybe if the signal was weak or something the direct connection might helpl it out....that's why I had it wired that way in the end...knowing it didn't make a difference, I will put the vid connects back onto the jamma harness this time so assuming I get this resolved I can play some other jamma boards in it too. Meaning when I wire back up I'll have the IO card back in the loop.
As for the wiring issue mentioned by notherngames, I had it wired exactly that way prior to reconnecting fighting vipers...so I find myself confused again, wondering why others have theirs working and mine is determined to taunt me with rolling screens filled with awesome games I can't play.
I also took a little look around when I changed the plug back to see if anything was obviously wrong...didn't notice anything obvious....but something did stick out to me....probably not relevant, but when I plugged it back into the high plug there was a gratifying snap as it locked into place like it's supposed to....the reason that stood out to me is because I felt like the low plug did not do that...call it a paranoia feeling if you will.
Anyways, I guess that gets us all up to date...will check back in once I reconnect the naomi stuff; in the meantime I am wide open for any and all ideas. Thanks again everyone!

[northerngames]

if you had the H and V connected by game output to the H input on the monitor and it still rolled then it is something different then what I had going on.

when your swapping the harness plug for low/med res your monitor should be unplugged from the psu wich also has a built in isolation transformer and could be why your hearing a snap noise 

[gokun]

Yeah; that would make sense...but I was actually talking about the sound the plastic connectors make when they seat properly though...my bad for not being more specific(I'm kinda bad about that)....and thanks again for offering your input-I really do appreciate it from all you guys who have responded-Thanks!!
On to the good news---It's FIXED!!!!!! YEAH!!!!!!!!!!!!!!!!!!!!!
For those of you keeping score at home, I took grantspain's advice and reconnected the fighting vipers which worked. So after reconnecting everything back for the naomi I decide to pull out the "other" naomi(with the broken fan and cracked case and rigged up IO card-and I do mean rigged; did the work myself so you just knokw it's poorly done^_~). I hook up the "other" naomi and.......perfect picture(well, almost...I need to do some minor adjusting now since I've screwed the pot settings all to hell mucking about with them; but I digress)!!
So I wonder what gives?!? I played that first naomi all the time until I put it in the cab and never had an issue....then it hits me...I always played it through my supergun(which of course has a converter card that takes care of all the sync, etc and regulates it all)....D'OH!!! Well at least I'm back in my own realm now....so after tinkering about a bit I find....(drum roll please)....the VGA plug on the first naomi is bad. Well, not bad per se, in the sense that it still functions but bad in the sense that the signal coming from it is corrupted(for lack of a better way to describe it)...thus no sync on my monitor. Do some more fiddling and discover...the solder pads for the old rgb connection on the naomi still work fine-woot!! Now both of em work in the cab and I can finally wire up the rest of my buttons and get to some playing(arcade night just isn't the same for everyone without project justice!).
So there you have it in a nutshell...as I've read sooooooo many times going through these forums looking for the answer, it WAS, in fact, a sync issue(just like everyone always seems to say). So I wasted about two weeks because I was too dumb to realize that my naomi could have a sync issue depite the fact that it worked on a supergun. For the record it also works on my other arcade cab...but that one has a MUCH newer monitor that supports a much wider range of freq too...if only I'd thought of that before. And as joey from jomac said to me in his email, these nanao monitors are not forgiving AT ALL when it comes to sync. It's either right or it don't work. So now you have my story, my stupidity, and the solution(see-I really DID read the rules before posting!).
On another bright note, I've now learned more about monitors than I ever wanted to know, and I thank you all for that. Had it not been for all the reading I've done here lately I wouldn't have even known where to begin; so again, I sincerely thank you all! More specifically I've learned a lot about nanao monitors so hopefully I will be able to help someone as well in the future. See you guys around-I will definately be around-I likes these forums a lot!