Hart task to find out what is wrong here - sruddy !
A professional service specialized on slide projection repairs may be much smarter as we both together ?
But there is no guarantee that you'll find such service wich is able to solve your problem ....
!
The one guarantee I will give you that it would be expensive in boths ways (solved or unsolved via repair service)
Help yourself and solve problems by yourself :
spent 50bucks and slaughter - perhaps you'll soon need parts in addition.
with regards
PS : If you have slaughter this machine from above in total - you A R E and expert - belive me !