The "O" reset goes like this:
Turn on the player
Press the "O" button for 10-12 seconds until the unit turns off and recycles
This will reset the player
As for card readers, which I have been using since I purchased my Pono on 05/09/15, it should plug in and configure automatically. It will show up as a drive on your machine. At least they always have on my PC's. Then you can just "drag & drop" music to the "music" folder. It is WAY faster than using the Pono directly.
Let us know how it goes...I would try a couple of other cables if you can just in case. If it still won't configure you may need to contact Phil Baker at Pono (pbaker@gmail.com). He can give you some options. Pono is still selling units directly for $200 plus shipping last time I checked.