PS3 slim will not take disks or spin but will eject disks if a disk is

Starting from the beginning. The first time I took my ps3 slim apart was because it wouldn't read disks. I changed the laser and got to work. Hooray!

Then I took it apart again for a presentation for school with a disk inside. Now I have some trouble. I have taken apart several times, tinkering around with the disk drive with no luck. The little white piece of plastic wasn't allowing disks to enter. I got the plastic to go down some how and then it would eject disks but not take them. and I don't think it's spinning them either.

So I bought a whole new disk drive and it didn't do anything to help. still won't take disks, but will eject them. I don't know what else to do I don't want to take it somewhere to be repaired. I don't even know where I could take it and I have asked reddit for help but got no answers. Hopefully this place will help me.

UPDATE: Tinkered around some more. I swapped the old circut board and put it into the new disk drive. Now, it will take disks and spin, but eject it out. The little gears will spin without a disk inside and the eject button blinks.