I can’t guarantee you that. A first step would be to open your phone using the iFixit guides and clean out any dust around the power button. Also look for weak soldering points and other damages.
In case that doesn’t help, have a repair shop inspect the problem and ask if they could do the soldering. (We have a list of repair shops with prices.)
PS: some follow-up reads: https://forum.fairphone.com/search?q=blue%20flashing%20screen