Last year I've bought a Jaleco Pony Mk.III, working but in a really rough state (some rust, bad paint job, all the electronics absolutely covered in dust, etc). It's my first arcade machine, so I've been slowly learning all the aspects about owning and operating one. The long term goal is to restore it properly, as in having it completely rewired, sandblasted and powdercoated, etc.
Until now I stayed away from the electrical part (except switching boards every now and then), since I know very little about electronics and the wiring is a mess. I didn't want to deal with it until I learned more.
I've been using it every other weekend, a couple of weeks ago I turned it on and noticed the game didn't start; the monitor turned on though, as well as the fluorescent tube. Tried switching the boards (I only own two pcbs, Final Fight and SF2CE, both bootlegs) and the behaviour was the same. What I noticed is that the switching PSU's light didn't turn on anymore.
So before doing anything, I decided to try to understand the wiring and document it, so I know what's doing what. Here's a couple of pics of the wiring, and the diagram I came up with (it's not 100% complete):
I could test and discard the fuse (made a continuity test and it works ok), and ordered a new switching power supply (this one: https://articulo.mercadolibre.com.ar/ML ... quantity=1, it works both with 110v and 220v). So the next step is trying to replace the old with the new one, and here is where I have some questions:
- I live in a 220v country (Argentina). I thought that the big transformer in the left was the isolation transformer of the monitor; but while inspecting the chassis I found it has its own smaller transformer. The monitor chassis says it's 220v, so I'm beginning to think that the switching PSU is the original 110v japanese one (since every terminal matches exactly the schematics of the Pony Mk.III) and the big transformer is a step-down one. Is this correct? Here's a picture of the chassis:
- So, if it's a step-down transformer, could I just remove it along with the old power supply; and set the new power supply to work at 220v? Or should I just change the PSUs and use the new one at 110v?
