The CD player in my Beocenter 9300 is not working.  The doors close, but I notice that they touch the top of the CD nearest the control panel when closing, as if the CD platform is sitting too high. Should this happen?  When I press "play" the word "stop" illuminates on the panel and the door opens.  It appears that the CD has been turning. Had it repaired by the local B&O repairer in 2004 - 1 new CD bc9300 w/pcb (8420217), 2 new Belts bc9000 (2732076) and the labour cost (2 hours).  The CD player worked for less than 6 months.  I have done nothing since, as we have a more recent player - and I thought I might be able to do something to fix it myself!!  It is not a matter of cleaning - I have done all that, with no positive result.  Was the right mechanism installed?  Why would it have failed so soon?  I know I should have gone back to the repairer, but you can appreciate I wasn't impressed.  Can  anyone tell me what I need - equipment - to rectify the situation?  Can any tech-minded person install - or does it have to be a B&O specialist (only one B&O repairer in this city).
I have edited the above, since original post, to provide more specific facts. 
Christine