hi all this is my first post. i have a mk4 in my z4 2004 it had the old maps with very poor detail so upgraded the firm wear which went ok then put in 2012 maps disk and it said please wait 2 hrs later still waiting i contacted the seller who said the lazer had gone weak and needed replacing which i did very carefully no big deal but when i powered it up it wouldn't eject the old i had in, opened up unit got old disk out now it wont take any disk in, looking into disk slot there are two little black bit stopping the disk going in,i have tried all the suggestions on site like holding eject while powering up for 3 mins boot open key in but not on just in case the unit thinks the disk is still in drive because i manually removed it and is trying to stop me putting in a second disk,also tried removing plugs at rear for 30 mins, about ready to give up now and leave it,would appreciate any help.