I'll note here for the Zero88 folk that trying to find spare parts and similar hardware support on the Vari-lite pages is fruitless if you are outside of North America (US/Canada/Mexico). There is no selection for Europe/UK/Asia and the "old" links on the Zero88 website don't work for spare parts or European/UK distributors etc (or at least those I found on the Blue Room [e.g. https://www.blue-room.org.uk/topic/61134-zero-88-fat-frog-psu/?do=findComment&comment=497542] or this forum).
Searching the Zero88 site for "PSU" or "spare" comes up with nothing or takes you to the Vari-lite page for distributors which suffers the geographical limitations stated above.
At this point Zero88 support for the common man outside of Vari-lite's traditional NA territory has just disappeared. If you're "in the know" you know where to turn, but the Vari-lite website doesn't do that for the general populous of non-NA Zero88 users. Maybe there is a route through the Vari-lite website, but as a "casual user" I couldn't find it. Can this be addressed?
Finally google found me a page (no idea how I'd get there otherwise, and going back "out" to the Vari-lite main webpage, I can't see how I'd get back here): https://www.vari-lite.com/global/products/frog-series#_spareparts
For the OP - the official part number is thus: 5537500