I am sorry for all the people having problems, but my Prusa mjni is finally just workjng and happily printing all the stuff I throw at it. Its been having issues here and there forever. I just figured out that the hotend has not been assembled correctly (heatbreaker to nozzle seal was weak) which became a greater issue when switching to a 0.25mm nozzle. Now after I fixed it, it is just awesome :)
My original Průša i3 mk0 has been going for 11 years now. It did receive a mk1 upgrade at some point when 3mm filament was getting scarce.
The IEC heatbed connector melted twice. But it’s been solid since I replaced it with an XT60.
Looks like I’m finally getting some metal fatigue in the heatbed temp sensor. I’m considering a new printer. The rest of the components are probably close to giving out after all these years.