I have an i3 Mega S, and recently I noticed that the prints were looking poor in comparison to my other printers. I finally figured out that the part cooling fan wasn't running. In Cura, I have it set to 100% starting at layer 3. I can adjust the fan manually from the touchscreen and it will remain at that setting. If I go straight to another print, it will stay at that setting from layer 1, but if the machine is switched off it will default back to 0%. I've had the machine since April, and it was only turning out ppe headbands, so I don't know if it was doing it from the start as they''re pretty basic prints. I have 3 other machines and have been doing this for about 3 years, so I'm pretty sure it's not my Cura settings (famous last words...). Any ideas?
I think it's cured now. I'll leave this here in case anyone else has the problem. It appears that there is now a setting in Cura to switch between fans if you have multiple extruders. In the settings/printer/manage printers/machine settings/extruder 1, make sure the fan number is set to zero.