Nanao MS9 to Wei Ya 3129A Chassis Swap Guide

[Ordyne]

The manual does not show the location of the focus and screen volts pots on the flyback transformer, so here they are:

Those are listed the wrong way around.. focus is at the top.

[dmauro]

I think on my Wei Ya they are in that order, but on my Nanao they are in the opposite order.

OP updated with instructions on how to connect to the PSU for power and to jamma for video.

[capcomguru]

Did you ever resolve the rotation pot issue? The weiya equipped to my blast city monitor does absolutely nothing...

[Ordyne]

I think on my Wei Ya they are in that order, but on my Nanao they are in the opposite order.

OP updated with instructions on how to connect to the PSU for power and to jamma for video.

I've never seen a flyback yet manufactured that way and also never seen a wei-ya like that.

[dmauro]

Did you ever resolve the rotation pot issue? The weiya equipped to my blast city monitor does absolutely nothing...

I contacted Alva Amusement about getting a rotation coil from them since it didn't come with the chassis, but they did not reply.

[cgbartek]

Sorry to bump an old thread, I just wanted to say this article was very helpful in getting my Wei-Ya 3129B hooked up to a Blast City. I thought I was going to have to cut some wires up but it turns out it's completely plug-and-play.

The picture looks great, the only issue I'm having is a slight convergence issue on the sides and slight compression on the right side. I know this is a common problem for this chassis and has something to do with the yoke, and there's not really anything I can do about it, correct?

To me the issue is minor but it would be nice if there was a solution.

[grantspain]

a few have been experimenting with high voltage caps for the side compression but no positive results so far
tbh it would take some like ordyne,jomac or rick nieman to get to the bottom of this problem

[dmauro]

I'm happy enough with the 15KHz image on this that I think I'm going to do it to my other (vertical) cab as well. It will be nice for the couple of hi-res shmups that I'd like to play on there, but also, I'm just running into all sort of headaches in trying to get my various consoles working with the MS8 chassis through a video amp. I would have already done this if it weren't for the $150 price tag. Yes the scanlines are just a little bit more pronounced on the wei ya, but certainly not enough that it bugs me. I'm looking forward to playing some Under Defeat on this thing finally.

(I'm going to see if I can get the rotation coils with the chassis this time)

[Pat70]

I have had a trisync chassis for a few months now and still have to swap it on my Astro ms8. I have a few doubts though of the pic. quality in 15kHZ...Can you post some pics of it running in 15Khz to convince me to swap?
thnx!

[dmauro]

Yeah, I'll try to remember to post some tonight.

[dmauro]

Comparison photos, finally! Something is weird about this VGA splitter and it's not carrying some pins which some how makes the PC's video signal weaker on the Nanao chassis (the Wei Ya is as normal though). Anyways, here they are:

Wei Ya Grid:


Nanao Grid:


(here's a close up of that compression to the right on the Wei Ya)


Wei Ya Circles:


Nanao Circles:


Wei Ya Solid White Line:


Nanao Solid White Line:


The compression on the side is a bit sad, but to be honest, it's not nearly as bad as the problem I'm having with my Nanao chassis as demonstrated here. In the lower left corner of the screen, when a ship is moving around, it causes a bit of warping. It's much more noticeable and jarring than any compression (which would be at the top of a vertically oriented screen, or the right on a horizontal, so the opposite side as your ship). The other problem with the chassis is, as you can see in the solid blue line, that a little bit of blue bleeds out. You only see this in games with light text on dark backgrounds, like old Namco games for instance. The Nanao doesn't do much better though with a little bit of color bleeding out as well, but what's worse is that it kind of fluctuates. I tried to capture it with a video, but it didn't come out. But even if I pause the mame emulation, you can see everything has a slight bit of bleeding that flickers. It's not terribly noticeable, but I'd rather have the steady blue bleed on the Wei Ya.

So I'll probably have two MS8 chassis available soon if anyone is looking for some

[Arcadeben]

Thanks for the update. That is great news you are going to do the other monitor also!

[dmauro]

I forgot to mention that Wei Ya chassis also appears to be rotated about 0.1 degrees clockwise (I came up with that estimate by rotating a 4:3 block in photoshop to about the same amount my image is rotated). But now that I'm getting excited about Under Defeat and Shikigami no Shiro 3 in hi-res, I'm not too worried about it. The chassis shipped out yesterday, and last time I got it quickly, so I should have it by tomorrow I would imagine.

edit: and I take it that blue bleeding is the blue convergence being off? That's not something I'm particularly keen on messing with if it is.

[Arcadeben]

Was it still 150? I am considering picking one of these up. And the 5pin to the dsub adapter was included in the packaging right? Also was the power adapter included, or did you have to make that up?

[dmauro]

Yes! $150 + ~$13 for shipping to NY. And they shipped it out the day I ordered it (best to just call them up, you can get their number on alvaamusement.com). TWO power adapters are included! 15pin AND a three pong power outlet style. And the d-sub adapter is included as well. The only thing this didn't include is apparently it needs the rotation coils for the rotation pot to do anything, and unless they are tiny and I missed them, they didn't come included.

Also, you might want to wait until I get this one installed (hopefully this weekend) to report back that it works as well as the other one. Maybe I got lucky with my first chassis and I'll get this new one and it will have worse geometry or a collapsed horizontal width or something weird.

[Arcadeben]

That is a good idea. I can't wait to see how this other one turns out for you.

[dmauro]

Just put the new one on today and it seems to be great as well. I don't have it fully calibrated yet because I realized that part of the problem is that my PSU in this cab sucks, so I'm just going to plug the monitors power directly in with a three prong, but I played a game of Under Defeat and broke a million and got to Stage 4 without even trying. I'm really glad I made the swap, this is going to be great.

One weird thing I noticed: this monitor was vertical, and I pulled it out and set it horizontal to put the chassis in. When I plugged it in and powered up, the screen has degauss related discoloring. I tried turning the monitor off and back on to activate the degauss, but couldn't get it to go. It's fine now that it's vertical again, but this thing is supposed to degauss everytime it turns on.

[grantspain]

the degauss only functions from cold,i.e after 3 hours non operation.
if you tate the screen and wait it will right itself

[dmauro]

But this was the first time I was even booting it up so it was totally cold and it didn't degauss.

[dmauro]

I'm having some problems with the new chassis. The weird thing is, all of the problems come and go and seem to depend on where the monitor is. I thought maybe it was related to different cables getting too close to high voltage stuff, but I haven't been able to improve things by moving wires about. When I pulled the monitor out to take a look, the screen looked like this. It's kind of hard to tell on youtube, but there's lots of noise. That's when it's at it's worst. I couldn't find any obvious problems on the chassis so I put it back in the cab and it got back to how it started, which is almost fine except for some kind of flickering as seen here. In 31KHz, it's totally playable, but the flickering is pretty annoying. In 15KHz, it's the same except there are occasionally moments of total weirdness, as seen here. And it gets even weirder too, I wasn't able to catch a video, but sometimes for a few seconds the image will be completely garbled. Totally insane as if the sync signals are way off with lines of color just kind of shooting around on the screen.

All the while the monitor makes an extremely high pitched whine that you can just make out. My original 3129a chassis doesn't make any noise, so it's subtle, but definitely noticeable. The only thing I can think of that might be wrong is that I accidentally sent power to the chassis before I connected the FBT connected to the back of the tube. The FBT wasn't touching anything, however, so it wouldn't have sent high voltage to any part of the chassis, but I'm worried this might be the source of the problem.

Anyone have any ideas how to fix this thing? Thanks, guys.