There is no absolute "right" way..... so everyones opinion should be looked at.
As far as the isolation transformer goes..... use your old one. Even if you bought a new one you would still have to wire it in anyways. The one you have is already there.
My point of keeping the old power supply in there is simply because it's already setup for the monitor's isolation transforemer, an EMI filter, cabinet switch, fuse/breaker, and all that sort of stuff that you will then need to rig up if you take it out completely.
As far as putting a power strip in there to run the pc or any other pc related equipment..... you should be able to tap into the 120 right inside that original power supply, then it would all still operate on the original cabinet switch as well. (don't even need a
smart strip) Flip the existing cabinet switch and everything comes on, except maybe pushing a button to boot the pc which is typical anyways.
Eliminating the original power supply would also mean that you would then still have to wire up another power supply in order to use the Jamma harness for Jamma boards because they will require the DC voltages.
The Jpac doesn't need any of those DC voltages and they recommend removing the original power supply, but that's really only if you plan to have
just MAME in there.
(less clutter so to speak)
It doesn't hurt to leave it in beacause none of the jamma voltage pins are even used on the Jpac while it's plugged in.
So going from a JAMMA cab to a MAME cab and back would then simply be a matter of unplugging the Jpac and plugging your JAMMA boards in and vice versa.
And as far as MAME and the PC goes if the only thing you find that you need to plug in is the actual pc power supply then you may be able to just plug it into the existing power supply without doing anything to it. Just depends on how much "other" stuff you plan on plugging in as to whether you need a power strip at all. And if it's just the pc power supply then I don't think it should draw more than the auxillary outlet is rated for. (see pic below) Either way you look at it, both the original power supply and the pc power supply will not be running at the same time even though they are both there. The outlet on the outside is usually underated because it's a cheesy cheap outlet, if you harwire to the inside it should do just fine.
I'll open one of mine up and take a pic of it and point out the few known things to consider. (if my crappy camera will get a decent shot indoors) Your pictures have been great to work with.
I'm sure I whizzed right over several details, but to give a general idea that everyone can come up with a method of doing things. You just have to take it all in consideration and develope your own plan of attack. Pop the top open on your cab power supply and take a peek in there. (nothing fancy there)
