The electrical adapter? No problem with the two fountains I use (one in Switzerland, the other abroad), bought more than 4 years ago.
For details of the adapter: PET MATE, Model 33504, Pri: 230-240V, Sec: 12V - 200mA 2.4VA -
https://www.pet-mate.comIn any case, the replacement is available check Galaxus, see
Cat Mate Pet Fountain spare pump (possibly check the version).
All in all, I prefer ceramic or stainless steel cat fountains. Less cleaning.
A general recommendation in the event of frequent problems with adapters: use plugs/multiplug sockets with surge protection/filter.