After a long time not using the printer...
I have a MK3S and recently tried to print after being idel for some time, and it was a disaster... can anyone advise where to go from here? What kind of maintenance should be done?
Your first problem is the dirty print sheet - so:
The three common reasons for prints suddenly failing after a printer has been unused for a while:
A dirty print bed. Give it a really thorough clean and avoid touching the print area.
Damp filament. Look up threads here about drying filament especially if it has been left open.
General neglect, dust and cobwebs...
Basic cleaning, lubrication and general maintenance have all been missed.
See: https://help.prusa3d.com/en/article/i3-printers-regular-maintenance_2072
https://help.prusa3d.com/guide/maintenance-tips_23200
Cheerio,