Print quality trouble shooting guide by Simplify3D software - this is not slicer specific.
It's a good idea to print and install a filament filter/wiper - It's a small box with a sponge inside that just wipes the dust off the filament. You can find several designs on Thingiverse
If you need to install new fans (you probably will) this information might be useful;
A control box replacement fan that works.