Leaving a movement (FP3 Era)

[AnotherElk]

@pedro

Unfortunately the motherboard is no longer available

Source?
It isn’t sold in the shop, and wasn’t at least most of the time. A reseller sold it only for a limited amount of time, too.
Fairphone can still exchange core modules as a repair job …

https://support.fairphone.com/hc/en-us/articles/211437743-Fairphone-2-repair-price-list-and-FAQ-Rhenus

@pedro

and there’s no information on how many of the other spare parts are left…

True.

@pedro

will still be batteries left when I need the next one? Probably not, as it happened to me and a friend of mine with the FP1.

Fairphone 1 users can use generic batteries. Better than nothing.
Whether there are fitting generic batteries for the Fairphone 2 would be worth some research I guess, but right now you can still buy original ones.

Generic battery to replace FP1 battery (see first post for warning)

This post contains instructions that can cause severe harm to you. Opening and modifying batteries is very dangerous. The battery is the most dangerous part of any phone. It has in numerous cases been linked to explosions, wounds and property damage. Just search on the internet and you’ll find them. Fairphone employees have seen with their own eyes the issues involved in the process of manufacturing batteries. The health and safety of the workers involved is very often i…

@pedro

I can no longer buy a motherboard, which I need to fix my mother’s phone.

You could try to buy a second hand module or a second hand Fairphone 2 containing a working core module via the Market.
Or you could try whether Fairphone can give you a quote for exchanging the core module, although I suspect they would want to make sure whether that’s where the issue lies. You’re right that reliability issues are tricky in that sense.