Hi, I've no part number to give you but I've sucesfully swapped a CD block from a BS3000 MK1 et BS9000 MK3. You may find the reference you're looking for by searching for "Beosound 9000 laser" on BEoworld II (link in the menubar). It seems that laser is quit difficut to source but not impossible. B&O may also afew still few of them but at crazy prices. Nevertheless, unless you know something about the fail (like having drop a coffee on the head or something similar!) chances are you just need a deep clean of the lens. It involves dimantling the laser lens and cleaning it inside-out. There again you should find a link to the youtube video on this forum. Good luck.