Nanao MS9 to Wei Ya 3129A Chassis Swap Guide

[grantspain]

you will need to check your earth is good to the chassis,also post some pics of your install so we can see where you connected the wires
make sure the dag earth is connected to neck card,are you going via an iso transformer-if so then run it from the wall socket instead to see if you lose some of this interference
check you have the signal switch tot he correct setting
check the 31khz freq pot is adjusted correctly
check the b+ voltages are set correctly(i have a guide to do this)

[dmauro]

How do I check if my earth is good? The wires I've installed exactly how I did with my other chassis. Here's a photo. The neck card seems to have all it's connections pretty secure, but I'll double check those. And I have tried running through the wall and through the cab's 15pin power supply, both have the same result. The signal switch is at 75, so that's good. How do I check the 31 and 15KHz freq pots, and where can I find your b+ voltage guide? Thank you, grantspain. Always a big help!

[grantspain]

i can't see the dag earth connected

[dmauro]

There are two sets of wires running from the main to the neck. The instruction manual doesn't have any clues as to what exactly the wires are. What exactly is the dag earth and how do I identify it?

[grantspain]

the dag earth is the earth braid that stretches over the tube,it should have a black wire connected to it that then terminates in a single plug-this connects to the neck card

[dmauro]

Okay, yeah, I forgot to connect the degauss coil (as I noted above, it didn't degauss when I first connected it like it should have; mystery solved) All taken care of now.

I'm still getting a bit of flickering though, but the image was perfect before I put the monitor back in the cab and used the 15 pin connector for power. Is it possible that the voltage being routed through the power supply is causing this? I'm going to try using the three prong connector and see if that works better. I tried that before, but that was when the degauss coil was disconnected, and I didn't notice a difference. I can't imagine what else it would be. It's next to the refrigerator, but it's the same regardless of whether or not it's running.

edit: Just tried it out with the three prong wire for power and it didn't help. I unplugged the 15pin connector and powered the monitor directly from the wall and the flickering was the same. It was doing this to a lesser degree. I'm sure the image looked perfect when I had it out of the cab though (although the whining that occurs when there is no video input persisted).

[grantspain]

you did not answer the question about the dag earth connection to the neck card
the last time is saw that type of waves through a monitor was when the transformer affected the monitor-if your dag earth is fine then move the transformer away from the monitor-that would explain it working fine out of the cab

[dmauro]

Yeah, I'd take a rotation coil off your hands for sure! Let me know how much I owe you. And my whining occurs immediately from the start, but it only happens when it's not getting a video signal.

So I have the dag earth connected. I did connect it, but it didn't seem to do anything helpful. I tried both the neck card and the main board (the manual says it should be connected to both, but I only have one cable from the dag earth). I confirmed that the signal is only getting the weird noise when it's in the cab, but actually, I can JUST barely see the noise when it's out of the cab as well, but it's so feint you would only see it if you knew what to look for. Here's the weird thing about it being in the cab:

There is a PC in the cab as well, it is plugged in to the wall, not plugged into the cab in any way. The cab is plugged into the wall as well. If I keep them plugged in the noise in the cab is at the normal mildly annoying level. If I unplug both the PC and the Cab from the wall, the noise gets WORSE. If I only unplug one or the other, there is no noticeable change. When I had the monitor out of the cab, I was plugged into the same plug in the wall, so it's certainly not anything to do with that wall outlet (and the other monitor that's fine is plugged in there too). I even tried moving the cab around thinking maybe there was something there causing the problem in that specific area, but that didn't help either. I tried plugging and unplugging the 15pin connector, I tried earthing or not earthing the pot board that goes in the CP, I tried powering through the 15 pin or through the three prong to the wall, I moved wires around to make sure nothing was getting too close to anything else. I even tried connecting the monitor when it's out of the cab, to the frame of the cab with a wire to see if it was the physical contact with the metal in the cab. None of these things made a difference. I'm totally at a loss here.

if your dag earth is fine then move the transformer away from the monitor-that would explain it working fine out of the cab

What transformer are we talking about here? Because the FBT comes out with the monitor of course.

[grantspain]

your cab must have a mains transformer in it somewhere-that is what i am referring to

[dmauro]

Where would this mains transformer? Would that be something in the PSU? And wouldn't it have no effect when unplugged? Instead, the noise gets worse.

[grantspain]

you must have a mains isolation transformer as it has a nanao ms8 in it originally
also a bad earth will cause similar problems
noise in the mains will also cause problems
easy to prove what is causing this by just removing the entire monitor from the cab and then running it,problem goes then transformer too close to crt

[dmauro]

I'll take a look at the manual tonight and see if I can figure this out. The transformer would probably be on the floor of the cab, so it couldn't get much further away from the monitor, so I'll probably have to replace it. But how would the transformer be causing this problem if it's unplugged? Wouldn't it have to powered up to cause any interference, or does it carry a residual charge or something afterwards?

[grantspain]

hang on i am getting confused here,so what you are saying is that you are running the monitor in the cab but using an external video input source and everything in the actual is powered off
or
you just disconnected the power from the transformer to the monitor

[dmauro]

hang on i am getting confused here,so what you are saying is that you are running the monitor in the cab but using an external video input source and everything in the actual is powered off

this.

I am running video in from the PS2 at 15KHz and the Dreamcast at 31KHz to test (they are in the cab next to it, not in the cab that is having problems). And I can power off the cab entirely because there is a three prong power cable for the chassis that allows it to plug directly into the wall.

[grantspain]

urm,and it does this with a jamma board in it or only with whatever converter you are using from the consoles?

[dmauro]

I don't have any jamma boards to test, but since the jamma boards would be fed in through the same VGA input, I would imagine that it would. Every system has the same noise, The PS2, Dreamcast, PC, and Wii. They aren't using adapters, just normal VGA cables. This noise does not appear on the other Wei Ya fitted monitor, which is receiving the video input the same way.

[grantspain]

none of this really makes any sense if the monitor worked outside the cab unless there is still something disconnected
what you are seeing is the same effect when a transformer is too close to the yoke or when there is a serious earth related interference

[dmauro]

none of this really makes any sense if the monitor worked outside the cab unless there is still something disconnected

Yeah, that's why I was baffled last night. I mean, without even changing what was plugged in (power still plugged into the wall, video plugged directly into PS2), the monitor simply went from being on the kitchen table to being in the cab and the noise became a problem. The only things that are different is a) it's in another physical location which is near the fridge (but the noise continues even when the fridge isn't actively cooling), b) it's touching the metal frame of the cab, c) it's leaning at a bit of an angle as opposed to being more vertical when it's in the cab, and possibly d) some wires might be getting too close to something else (but as I mentioned, moving them around doesn't improve things).

[grantspain]

well of course you could move it away from the fridge to prove that.
i have seen on one occasion a beer cooler cause a similar problem but that way more powerful than a fridge

[dmauro]

It seems to be the cab next to it that is causing the problems (I had the other on one when I was testing last time and didn't realize it). The other monitor does not have a problem though. I guess this monitor is just more susceptible to interference? The funny thing is that having the cab and/or PC on helps reduce the interference. I guess it's just canceling some of it out. Separating the cabs by a bit more helps alleviate some of the problem, but doesn't remove it entirely. I'm going to have to find a way to shield the one monitor from the other I guess.