Chosen Solution
I followed the ‘problem’ steps from the manual, but the flashlight is still not working. before it stoped working, from time to time the flash worked, making a popping sound when making a picture. I think, it is broken and needs to be replaced. but how, do I do that? and were can I find a new flasher?
Your best bet it to put a watch on eBay for a “spares or repair” camera of the same model but with a different fault. It should then be possible to swap out the flash module. You can practice disassembly on the one from eBay before attempting yours. BUT: make sure you understand the danger from the flash capacitor and how to avoid it - this can hold a charge at a dangerous voltage for many hours, or even days, after being switched off.