I am a Korg dealer in California. I have complained to Korg many times about the condition of their keyboards when they arrive from New York to my store in California. Almost every keyboard that we receive, including Tritions and PA80's, the white foam inserts that hold the keyboard in the box are cracked and many times destroyed. This allows the keyboard to freely move around inside the box. This motion can't be good for the boards. I've been told that when the keyboards arrive in New York from Italy and Japan they are shipped on slabs, many stacked together. When they leave the wharehouse and are shipped to the dealers, UPS and FEDX are much rougher on these individual packages and so they often arrive in pretty poor shape.
Because of so many operating system updates, almost every PA80 has been upgraded at the New York Warehouse and that is why other pages have been added to the original owners manual. Almost all of mine arriving the past few months have had pages wrinkled or torn and I assure you this is because of improper packaging.
I don't work for Korg, but if you are sure that your dealer has not sold these keyboards to someone else who has returned them and then repackaged them, then I would guess that the red fabric lint could be from Korg opening up these products in New York and loading in the latest operating systems. When large volume dealers have a 30 day money back guarantee, the amount of return products have to go somewhere! Again, if you know your dealer well, this may not be the case.
I would urge you to contact Korg USA in New York and speak with them about the condition of the PA80's you have received and ask them to do a better job of packaging. I do it all the time and maybe together we can get the results we need.
George Kaye
Kaye's Music Scene
Reseda, California