What's new

twistedsymphony

Enlightened
Staff member
Immortal
Joined
Jul 21, 2015
Messages
11,655
Reaction score
13,071
Location
NH, USA
I've got a Net City Upright. says "net city" on the legs, and on the bezel, and has the link board etc. it SHOULD have one of the Tri-Sync monitors but a few days ago I decided to try out some 15KHz JVS games (Konami System 573 and Namco System 12) and the monitor didn't want to sync to the 15KHz signal.

This has me wondering if my cab has a one of the 31KHz only chassis variants such as the MS-2932

If so I'm curious if I'd be able to simply pick up a tri-sync chassis, such as an MS-2931 and have it work with my tube. I'll need to pull the back cover off to check the tube PN and the chassis PN (I did have it off once before and IIRC it is indeed a Nanao chassis and Toshiba Tube).

Beyond this if I ever pick up a NAOMI Universal cab it'd be nice to know if I could make it tri-sync.
 
Presumably if the yoke measurements are within the same ballpark it should work? I would maybe explore some kind of sync cleaning first, since I know people have trouble getting the 573 to sync even on DDR red cabs, which have a trisync Toshiba in them.
 
I know people have trouble getting the 573 to sync even on DDR red cabs, which have a trisync Toshiba in them.
I've heard that, which is why I also tried the Namco System 12 PCB... and that had similar results. I suppose I could also test NAOMI in 15KHz mode.

it does sort-of sync... the video output ends up being twice as wide as it should be so you only see a portion of the picture. my initial thought was there was a switch or setting being missed, but all reports seem to indicate that the tri-sync Nanaos should auto-sync to 15KHz signals.
 
I started looking into this more, and started looking into if an MS9-29 could be swapped into place on an MS8-29 tube.

Here are the yoke measurements for all 4 (from arcade otaku wiki):

Nanao MS8-29 FAN
Lh 0.355mh
Lv 18.7mh
Rh 1.0 ohm
Rv 7.9ohm

Nanao MS9-29 T/SU
Lh 0.315mh
Lv 18mh
Rh 0.7ohm
Rv 9.3ohm

Nanao MS2931 (Tri-sync, curved tube)
Lh ??
Lv ??
Rh 0.9 ohms
Rv 6.8 ohms

Nanao MS2932 (31kHz, curved tube)
Lh 0.196mh
Lv 13.8mh
Rh 0.6 ohms
Rv 6.9 ohms

Here are some photos of 3 of the 4 neck-boards


MS8-29:
ms8-29_neck_board.jpg

MS9-29:
ms9-29_neck_board.jpg

MS-2931:
ms2931_neck_board.jpg


it appears that they should all be pin-compatible. I haven't been able to find a photo of the MS-2932 neck connector (if you have one please let me know) but from all accounts I've read it should be compatible.

looking at the photos the MS9-29 and MS-2931 neck boards look nearly identical.
 
I've heard that the 2930/2931/2932/2933/2934 chassis are all compatible with each other's tubes.

When putting a 2933 chassis on a 2930 tube, however, the heater resistor needs to be swapped on the chassis or you get low brightness.

When putting a 2933 chassis on a 2931 tube it's a direct replacement and works perfectly (I've actually done this swap myself).

I can't say positively since I haven't done a 31k -> trisync swap, but if it were me I'd probably just leave it as a 31k setup if its otherwise working. However, if you do the swap and end up having to replace the heater resistor it would be an easy fix for correct brightness. It may not even take that being required.


If you want a definitive answer, check with grantspain on AO. He's a wealth of knowledge on these sorts of things.
 
Would be interesting to find out if the 2931 could be replacing a MS9, nice solution to get a tri-sync in my Cyberlead other then that crappy tri sync Wei-Ya chassis...
 
I just measured the two yokes with my cheap Chinese inductance meter. Here's what I get:

MS-2931

Lh 0.193
Lv 15.66
Rh 0.55 ohms
Rv 6.9 ohms

MS-2932

Lh 0.21mh
Lv 15.12mh
Rh 0.65 ohms
Rv 6.9 ohms

No idea why the horizontal resistance on the 31 is so different to the on AO. I triple checked this just to be sure.

Honestly, I think you're good to go! The tube on the 2932 is more curved, so it might look somewhat wrong in the corners.
 
Regarding MS8-29, the yoke is "compatible" with the MS9 but the width will not be either over-wide or over-narrow; I don't remember which. I think it will be too narrow.

Off the top of my head, I think the MS-2932 tube is a Toshiba A68KJU96X, same as on the MS9-29, MS8-29, and D29CR55. The yoke for the MS8 is not compatible, but the MS9 and Toshiba D29CR55 yokes are fully compatible aside from the connectors.

Please let us know if swapping between the -293* series works. A friend and I have successfully swapped an MS-2934 tube with an MS-2930 tube, which were both more flat than an MS9 tube.
 
I asked Enrique at Sharp Image Repair about installing an MS9-29 Chassis onto my MS8-29 Tube and he had this to say:

yeah they are pretty compatible.

hook up the ms9-29 and let me know what kind of picture you are getting.
most important check the temp of the horizontal transistor. if it gets too too hot its prob not gonna work for the longrun. it will work for a bit then get damaged.

so hook it up and check your picture size. if picture is good but cant get it to size down with the regular settings we can modify that to fit no problem.
cleardot.gif
Sounds like he's concerned the HOT might get... hot I've got an IR thermometer and some proper MS9-29s in my Virtual On cab so I might see what the default Temp is for those and then compare when running on my MS8 Tube.

IIRC there's a cap you have to replace to adjust the size range, at least that's how it works on the WG chassis.

I've ordered an MS9-29 chassis, I haven't come across any MS-2931s yet but I'll be keeping my eyes open.
 
So I bought an MS9 chassis and I've been looking over the connections. it seems that the yoke connector is different.

The MS8 uses a 4 pin yoke connector, the MS9 uses 2 separate 2-pin connectors, and one of those connectors uses smaller pins (meaning I can't just cut the original 4-pin connector in half).

Anyone have any idea what this connector is, or if anyone makes a male 4-pin yoke connector so I could build an adapter harness?

the video input connector looks the same (though I haven't double checked that it's pinned the same). the power input and degauss output look the same also, but the degauss switch connector looks different. It seems though that both my original chassis and the MS9 have a sub-harness for video and power so I should just be able to install a new connector on this sub-harness to allow it to drop in. At that point the only issue is the yoke connector.
 
The MS8 yoke needs a physical adapter to work with the MS9 as you've noted here, but it won't quite work the same anyway. The width will always be wider than you'd like.
 
yeah, I recall you mentioning that before. I'm confident the chassis can be modified to fix that though.

the first step is just getting it hooked up though.
 
Back
Top