When I started getting the “Refreshing your media” issue at random times, I also tried any kind of cleaning I could do because I thought that was my problem. It definitely could have been, but I just wanted to post what had happened to my player (twice now) and how I fixed it. In short:
the SD card holder had broken solder joints and was making intermittent contact to the circuit board.
I realized this when I had it open for cleaning, and noticed that pressing down on the card slot/holder would make it reliably read the card. I probably drop the poor player on the floor at least once a week, so this is how the card holder must have gotten broken solder joints. I went all around the slot with a thin pointy tip (about 1mm, smaller would be better) on the soldering iron, there are alot of small joints so you really have to take a close look. Have done this twice now, it has been running fine for probably 1.5 years since the last time.
So if you’ve done all the cleaning you possibly can (like i had), this might be something to try.