Originally posted by Russell-Evans the main cause of faulty SDM AF is a bad mount for the small electric motor. He said a 25 cent (sic) piece of plastic
Russel, thank You for this valuable detail of information.
We don't know how frequent SDM motor failures are. But with 3 of your lenses fail, it may not be unlikely. Can you estimate #shots with each lens prior to failure (LR count or the like)?
If it is likely I assume that sooner or later, we all see our SDM drives serviced (~180$ repairs obviously). So, I have another question to you:
Did Pentax made a stronger SDM motor mount available, to be used as a replacement part when the lens is serviced, that it doesn't happen again?