My recorder works normally, sort of. I can record tracks on my Sony JE 510, but when I finish recording I get a "blank disc" message when I want play the tracks I just recorded. However, if I put a disc in that I recorded earlier, it plays back normally. This problem just started today, any discs recorded prior to today play normal, so I'm guessing that even tho it is indicating it is recording, it must not be recording? Any hints of what could be going on here, before I take it to the shop.