I'm not an electrician so forgive me if I say something wrong. I've got a system 1 (pinball pool) machine that is all original, no modifications at all, and both of the power supplies are toast. I understand that replacing the MPU with the Ni-Wumpf board eliminates the need for all but a "5V power supply". Replacing the displays with the Boston Displays eliminates the need for the 69 VAC. So if I replace the MPU and the displays, and use an ATX power supply to provide the 5VDC needed for these 2 items, what other voltages do I need to plan for? Does this eliminate the need for the driver board? Can I eliminate both the bottom panel transformers (remember, both of mine are toast). I have no real issues with getting creative and utilizing different power supplies to provide additional voltages but am unsure of what the remaining requirements would be, or if the 5VDC would take care of all the needs once the MPU and displays are replaced. Is there something somewhere that outlines the modifications I would need to make, including below the playfield? Any help would be appreciated.

I thank you for your quick response because I'm in limbo on deciding what parts to purchase, but unfortunately, as I stated in my earlier post, I'm not an electrician and am really unsure of a lot of things and need to get some specific answers:
1. by replacing the original MPU with a Ni-Wumpf (this board is only $178) that only requires 5VDC, can I eliminate both the transformers in the bottom panel?
2. There are 2 bridge rectifiers that provide 25VDC and 6VDC. I've tried to decipher the schematics but no luck so far. Did these 2 voltages power anything that the 5VDC doesn't power?
3. What happens to the power supply in the backbox? do I eliminate it as well?
4. Is the driver board still needed? if so, what will power it?
5. If there is a need for an additional power source, maybe for some of the playfield solenoids? I've found several options to provide a DC voltage of my choosing, but am unsure of what that voltage needs to be. Any ideas here?

As an update to my last post (several other people have replied since then) -
Yes I have the schematics but I'm not comfortable with interpreting them. Most of what I've seen (in the replies) seem to favor the Pascal board, so I will now reconsider my preference for the Ni-Wumpf board. From what I see on the picture of power breakdown, I would still need to supply 24 VDC for (playfield?) coils, 6.3VDC for general illumination, and (a separate?) 6.3VDC for CPU lamps, although replacing the MPU (is this the same as what was mentioned as CPU?) might eliminate the need for this as well. How much of this is correct?