Looking for Mains wiring advice

[Namco]

I'm at the part of my project where I must tear out the power supply, wiring, and Jamma board. But first I am documenting what makes it tick and how it's currently wired. There are some strange choices of wire color and a few things I don't quite understand, so I'm looking for a bit of advice before I tear it up too much.

I've drawn up a diagram in MS Paint of the whole getup:





A few things I notice is that the color of the wires coming out of the EMI Filter flop from white to black which I think is kind of strange. There is continuity between all four wires, which is probably typical of AC wiring, I don't know for sure.

There is a black wire going from a chassis ground screw on the EMI Filter go GND on the power supply, obviously it's ground, no mystery there.

On the Transformer (I think it's a transformer), there is continuity between the two top posts and there is continuity between the two bottom posts. There is also continuity between the black and white wires in all cases, except there is no continuity between the marquee and monitor power wires. I forgot to put the power toggle pushbutton switch in the diagram, It's on the white wire before the fuse.

I guess the questions I have is why does black and white switch places in this diagram? And does it matter? And what's the purposer of that transformer thing? Also, why have they tied earth ground to to the power supply's Jamma GND by connecting the EMI filter to it?

A

Anyway, if you electrical guys can tell me if this looks good, or how to improve it, let me know so I can implement it when I reassemble it all.

EDIT: Ugh another edit. I got it a bit mixed up. When the mains comes into the cab, right away white is spliced into a black wire and goes to the power switch. That's where black and white get mixed up, not coming out of the filter. Is this okay?

[grantspain]

the only thing i would leave out is the psu ground to the mains filter case ALTHOUGH many years ago some psu makes did like the ground linked to earth
otherwise the wiring diagram is good,to be honest your present setup(minus the crappy joins)looks o.k

[Namco]

Thanks for the look and the advice!

When I put it all back together, I"ll hook that marquee light up to a plug and stick it in a power strip and hack the power supply for the coin door lights.

Thanks for helping me figure it out. Just looking at it, I'm realizing that I can just about get rid of all of it and use a powerstrip and the pc power supply for everything.

[BobA]

To clear up the white/black flip flop on the emi filter you have to trace the wiring back to the plug to determine if the incoming white and black are correct or in error.

[Kevin Mullins]

Just looking at it, I'm realizing that I can just about get rid of all of it and use a powerstrip and the pc power supply for everything.

That "transformer" is an isolation transformer...... you will want to keep that in circuit depending on what monitor you are going to use.

Are you MAMEing this cabinet? (sounds like you are)

[Namco]

Wiring coming from the mains is correct. From the power cable plugged into the wall, the white wire gets turned into a black wire thanks to an ugly join, goes into a switch, then into a fuse. The real black wire from the wall goes straight into a fuse too. Coming out of the fuse, the fake black/real white wire stays black, and the real black wire comes out of its fuse as a white wire. The evil transformation is now complete. Fake white and fake black split off between the isolation transformer, marquee lighting, and power supply. Looking at the isolation transformer, clearly the fake white wire (which is really live black) is soldered onto the 0V post of the isolation transformer, and the fake black (which is actually mains white) is soldered onto the 110V/115V post of the isolation transformer.   

This is the cause of my concern and the reason for the confusion and post.


Kevin: Yup, I'm MAMEing this cabinet and after careful consideration will power the monitor using a power strip and its own power cable. However, it would be neat to use the power supply and transformer to power the monitor, marquee, and coin slots, but I realize it is probably better that i simplify things get rid of that stuff if I can. I think about the most fun thing I'll end up doing is splicing the marquee light into a lamp cord. Figuring out the wiring situation in the cab before removing it has really helped though. Thanks for identifying that isolation transformer!