Fault The CD changer does not work after changing lens. Lens change became neccessary when CDs will not play

Ok man first thing I need to know did you decide the Pickup assy was bad or did a repair shop?? I fyou did or the repair shop how did they come to that conclusion??? if a pickup is truly bad you cant just repalce it and expect it to work No my friend Im not saying your stupid or any of the sort just uninformed maybe.. If a pickup assy is replaced you must first off have the service manual to see where the rf terminal is to connect your scope to look at the rf pattern. Now you also must have the serviuce manual to perform the focus and tracking Offset adjustment as well as the focus and tracking gain alighnment. First thing you wanna do is adj the offset adjustment as this will set the focus and tracking coils in a center alighnment for the gain Now this is a very important adjustment my friend as if the offsets off on focus it wont play certan disc and if the tracking is off alighnment it will skip all over all of a suddenly for no reason. Now you must have a scope to see what bthe rf pattern looks like to do any sort of alighnment or to see what bthe state of the laser is in. as sometimes even new laser assys. need whats called a grating adjustment and you really need the right tools as well as the right equipment to do these adjustments with . A laser pickup dosent go out as often as most servicers says it does as there was a servey done with the Mishuta corp( panasonic) and 85% of returned pickups were not defective and should not have been replaced. Now im not sure on how much experience you have with this stuff but if your a hobby type repairer thats great but please you may be over your head so see if someone with the proper eqipment as well as the proper tools can assist you in this repair. And I do think its a good thing that you are trying My friend But without the right service manuals as well as the proper tools your spend a bundle and get Now where??!! GOOD LUCK