Power supplies, per-se are not that high tech devices, it is just that some manufacturers have them custom built for their systems and they are not available of the shelf which makes them 'proprietary'.
I have ran in to this for the early Mitsubishi systems where the P.S. are no longer made but Mits repair them for around $1500.00.
If they are single output type or even multi-voltage, a little 'reverse engineering' can produce a replacement at a fraction of the price.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.