Transformer Information for Recent MVS Purchase!

Hello everyone!

Recently I picked up a 4-slot MVS cabinet and during transportation, knocked the transformer out of place. I just want to double check the connections before I put this all back together. Basically, I would like to know if this is the stock transformer (I know these things rarely go bad but it would help to know if it were original or not to diagnose if there are any problems in getting it to boot) and the actual wiring hookups to the transformers (pictures would be fantastic for anyone who has access to them).

This is the transformer I have/that came with the cabinet: https://imgur.com/a/C0I36zs

This is the current wiring (I need to order a new power supply as whoever had this before butchered it): https://imgur.com/a/FFU4Vt8

I'm aware the molex on the right is the 5/12 for the board and such, and the 3/4 pin is power for the CRT...I just want to make sure there isn't a serious power issue in this before trying to boot it as I cannot figure out why someone would remove the EMI from the power supply entirely (unless it was running on 220???).

Thanks in advance!

I don't know ANYTHING about how it is wired into the 4-slot. I don't have an MVS or even an arcade cabinet.

I *suspect* this is used as an isolation transformer and also to normalize the output voltage to ~115V @ 1.0A. If your line is low, like Japan, you would have the input at 105V, and it'll bump it up to ~115Vac.

I don't really recommend plugging things into your house to test them, I'd personally use an isolated supply to feed the transformer. If you are going to, put it on a gfci outlet to avoid injury. If you wire per below (note the colors are your HOUSE colors.. if your house is wired to code... not the colored wires attached), you should be able to check the output voltage with a multimeter. Since this is an unregulated transformer, the output voltage will be higher than 115V. If your house is closer to 125V, the output will be ~125V, not 115V. Does this matter? It depends what plugs into this transformer. If this rant provides more questions than answers I wouldn't mess with the transformer at all.

What I REALLY recommend, is when you get a new power supply, just get a good switching power supply that has isolation and you don't need this transformer at all. Doing a quick google seemed to give results.

xwred5 said:

I don't know ANYTHING about how it is wired into the 4-slot. I don't have an MVS or even an arcade cabinet.

I *suspect* this is used as an isolation transformer and also to normalize the output voltage to ~115V @ 1.0A. If your line is low, like Japan, you would have the input at 105V, and it'll bump it up to ~115Vac.

I don't really recommend plugging things into your house to test them, I'd personally use an isolated supply to feed the transformer. If you are going to, put it on a gfci outlet to avoid injury. If you wire per below (note the colors are your HOUSE colors.. if your house is wired to code... not the colored wires attached), you should be able to check the output voltage with a multimeter. Since this is an unregulated transformer, the output voltage will be higher than 115V. If your house is closer to 125V, the output will be ~125V, not 115V. Does this matter? It depends what plugs into this transformer. If this rant provides more questions than answers I wouldn't mess with the transformer at all.

What I REALLY recommend, is when you get a new power supply, just get a good switching power supply that has isolation and you don't need this transformer at all. Doing a quick google seemed to give results.

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I appreciate the reply...I'm a technician with an arcade chain so I have bench access as well as location testing...which, now that you mention it, I can just call up a location with an MVS for photo identification. I understand 110 fully, like I said, I was just trying to trouble shoot as to why the original PS was ripped up (EMI was completely gone, inline fuse was completely removed)...like I said, I was trying to figure out if someone was desperate to get it up and running or if it was just a hack-job by someone who didn't know any better. I don't know the MVS that well (have only worked on one prior to purchasing this one) which is why I was asking if anyone could post some photos of their poewr setup in the rear of the cabinet (at least, that was my intent, reading back I don't know how well that came off). This cabinet has sat for a very long time but is in really good condition (none of the wiring outside of the PS has been messed with in any way as far as I can tell) and was complete (and I know the board works albeit with some graphical issues which I think is due to not being deep cleaned) which is why I jumped on it.

The power supply I ordered was the Suzo Happ 150w which is supposed to be a direct swap for the original/OEM PS...it's what I saw recommended elsewhere on these boards...but I've never seen one of these without a transformer? In fact, I don't recall ever seeing a cabinet of any kind without one...

Google tells me that it’s to isolate the monitor-which makes sense.

Just a quick update...wired up the isolation transformer...CRT works and looks GREAT.



Thanks for the help along the way everyone!