Originally posted by dnmtsn` ...The reason for the lens coming apart is this: there are two metal rings that are supposed to stay screwed together; one is silver one is golden in colour; the golden one is glued on the plastic chassis of the lens by a glue, or by applying heat (??); in any case, there is nothing to fasten that golden ring to the chassis, like a screw, nothing; it seems to be glued or it just stays there because of friction. What happened is that this golden ring disengaged from the chassis, remaining stuck on the silver one. This probably happened because of a slight decentration, making the friction between the two rings in a certain position higher than the friction keeping the ring on the chassis. In time, this un-stuck the ring from the chassis...so the lens came apart. At least this is what I understood and seeing the pictures all this made sense... .
I think it does too, looking at the photos on the Chinese site.
Quote: Putting it back is a major pain, because the screw on the silver ring has multiple start points and you have to find the right one otherwise the lens won't focus properly...
The first time I did this, not knowing it was difficult, I spent about two hours trying to get the parts back together.
Thanks for the update. I'm glad it worked out for you.