EDIT: NEW RELATED QUICK QUESTION!

[Honzo]

ok please don't flame me for this thread because i've been searching A LOT and can't find just what i'm looking for...
I have an MK2 cab that i'd like to turn MAME.  First step i need to do is gut the components, but since I got the monitor working, I want to keep it and use it, so I need to figure out how to power it.  Originally i was planning on tracing all the wires and figuring out how to remove all the unnecessary components, but came to find the "repairs" done on it had left the wires nearly untraceable (someone decided to "ghetto rig" in extra lights and such)  I did come across this diagram in my searches though....



this almost explains what i need answered, but not 100%.  on the diagram, it doesn't negate positive and negative from the monitor.  Now these could be written right on the isolation transformer, but i didn't want to pull it out before figuring out.  So basically, ac power goes on the bottom terminals and power to the monitor goes on the top?  And how do i know where the positive and negative go? does it matter?

EDIT: NEW QUESTION!
So i'm rearranging these components to independently power the monitor... Originally the isolation transformer and filter were oriented and spaced strange and I just wanted to make sure this isn't for any particular reason.  Do these two things have to be a certain distance apart? and should i keep the computer an other components away from the filter and transformer to a certain degree? I wasn't sure if the magnetic field produced by the transformer had anything to do with its awkward positioning.  Thanks!

[Kevin Mullins]

So basically, ac power goes on the bottom terminals and power to the monitor goes on the top?  And how do i know where the positive and negative go? does it matter?

It has AC voltage IN and AC voltage OUT.  (in this case a 1:1 ratio)
So there is no "positive" and "negative".
The monitor connects to the top two terminals as you said either way.

[MonMotha]

If this has the stock MK2 wiring in it, the giant transformer in the bottom is not a standard fare isolation transformer for just the monitor.  The whole cabinet is run off that transformer to allow the cabinet to be set for whatever the local AC line voltage happens to be (and sadly, there's no 1:1 setting documented in the manual).  This setting is made using the loops of wire found in the plug that goes up to the power switch on top of the cabinet.  These settings are documented in the manual which can be found online if you don't have a copy.

The transformer assembly will have a long AC line cord hard-wired to it going into the bottom of the box, and then several output windings on top: 2x 120V and 1x 6.3V.  The 6.3V winding (yellow color) was used to run the coin lamps and nothing else.  One 120V winding (purple color) is supposed to be dedicated for the monitor, and the other is for the DC power supply and the marquee light fixture.  Both windings are isolated from each other and of course from the incoming AC line.

On many (most?) cabinets, the wiring was done wrong, however, and the monitor shares with either the marquee fixture or the power supply (I don't remember which).  This doesn't usually cause problems due to other factors, but it's not right and can pose a safety hazard, and you might want to "fix" things while you're at it.

[Honzo]

I don't think its the stock mk2 wiring.  The cab has a sticker on the back for TMNT and the CPO is anything but stock, it think the cab's been recycled multiple times....  I checked the wiring again and i think i figured it out...

It looks like power comes into the cab, goes to the filter (or at least i think its a filter like bob roberts's diagram) [see pic], then (positive end) is fused and goes to the red wire splice [see pic] where it splices between the power supply and isolation transformer.  then the negative leads comes out of the iso trans and power supply and resplice to a wire that goes to the filter again and back out of the cabinet.  on the other side of the iso transformer, its fused again and goes into both the monitor and marquee light (wired parallel) and then back into the iso transformer

i've also included a picture of the transformer.  I hope this all makes sense....

[Honzo]

oh, also, the 2 tabs bent up on the iso transformer are the ones that were used, and its confusing at that angle but its the 0 and 115v ones

[MonMotha]

Oh, so this is a Konami cabinet, then.  None of the MK2 stuff applies.

Also, when taking pictures like that, use macro mode and hold the camera against a steady surface or use a tripod.  A couple of those pictures border on useless since they're a giant blurry and streaky blob.

AC wiring doesn't have positive and negative.  Incoming ("mains") AC wiring will have hot/line and neutral, and isolated AC (coming out of an isolation transformer) just has two wires with no real designations that can be interchanged.

Not sure what's with the large number of cabinets that seem to have their marquee fixtures running off the output of the isolation transformer.  It's unnecessary and can introduce some safety concerns as well as a ground loop.  Other than that, this sounds like a fairly "normal" AC wiring scheme for a cabinet like you have.

[Honzo]

first, about the pictures, i apologize.  Its actually a REALLY crappy cell phone camera in very low lighting, so thats the effects of a crappy camera and me holding 3 things with 2 hands 

second, sorry if i keep referring to negative and positive, i have a lot more experience with dc wiring so this is kind of foreign.

third, i don't think the marquee light is actually standard powered off the isolation transformer, it looks like a regular fixture with the back ripped off and the original power wires spliced in, but i could be wrong...

so to retort, this isolation transformer will indeed work?

[MonMotha]

Yeah, shouldn't be a problem.  Just wire things up according to that diagram you have from Bob Roberts.  That diagram is perfectly applicable to this situation.

[Honzo]

Thank you! I Appreciate it!!! 

[Honzo]

NEW QUESTION!
So i'm rearranging these components to independently power the monitor... Originally the isolation transformer and filter were oriented and spaced strange and I just wanted to make sure this isn't for any particular reason.  Do these two things have to be a certain distance apart? and should i keep the computer an other components away from the filter and transformer to a certain degree? I wasn't sure if the magnetic field produced by the transformer had anything to do with its awkward positioning.  Thanks!

[Honzo]

no answers?

[grantspain]

just make sure the transformer is as far away from the crt as possible,the proximity of the filter and transformer should not matter

[Honzo]

ok, thank you!