Thank you for your post. Actually, Pentax no longer deals directly with customers for after-sales service. Customers should pass through retailers.
The SDM motor failure is mentioned in various forums, with some pentaxians being very vocal. Compiling the feed-back, SDM lenses seem to be very sensitive to 'impact damage
'. Since I take great care of my gear, I'm surprised (understatement
I purchased one of the first lens available in France. Maybe quality wasn't on top.
Before being inert, my DA* 50-135 did a stuck focusing. In that case, the SDM motor was moving the AF painfully and slowly, as if the motor weren't powerful enough
My other SDM lenses, the 2 years old 16-50 and the 6 months old 60-250, both work perfectly and the ultrasonic motor is a true delight, fast and quiet. The 50-135 is the only one featuring internal zoom.
Anyway, I'm waiting for my lens and I hope I'll receive it soon before Spring
Pentax K-5 + BG4 + DA* 16-50 + DA* 50-135 + DA* 60-250 + AF-540FGZreivilophotography.weebly.com