DA* 16-50 Problem... :'(

I got my DA*16-50 out to take some photos this afternoon and was very worried to find that the SDM motor was not working at all. I had only used it two days before to take a few shots around Leeds and it had worked fine all day long then.

I did test it for a good while... half pressed the shutter, fiddled with the AF button, changed the focus lever and switch and nothing happened. I did the same on the 2nd K10D body we have and it was exactly the same. I was starting to sort out sending it to Pentax to look at, it was all neatly packed away.

I decided I'd get it out and have an other look. This time I heard movement within the lens, the AF mechanism was moving extremely slowly and in a jumpy manner, hopping half a millimetre or so on the distance indicator. I got it to move all the way through the focus range once each way painfully slowly. The next time I got it to move it focused at a normal speed but making a squeaky noise as it did so. I have heard someone mention squeaky SDM previously with their 16-50 on DPR forums.

It seems to have returned to normal apart from the squeaky AF noise. Does anyone have any similar experiences or suggestions?

I am a little worried as my only other lens my 50-200 is non-functional as it won't focus any more. Images are very soft throughout the focus range (thing 85mm soft lens soft but completely missfocused) and it is completely out of focus when set near infinity on targets far away. Things are not going well...

Yeah, mine is squeaky. It is still quieter than mechanical, but noisier than I'd like. The 50-135 on the other hand has always been really nice.

It may have something to do with the extending zoom mechanism which the 50-135 doesn't have.

Probably, but not unlike dozens of other lenses.
Unless they squeak too, but cannot be heard over the hum of the motorized focusing?

I guess, but it was very strange that it stopped functioning completely for a while.

Tyr : I had a similar issue with mine (16-50) recently.
It wasn't squeaking but the focus action was jerky and wouldn't focus at all
I took it off and gave the contacts a clean but this had no effect.
I then found the AF.S AF.C and MF switch was set in between the AF,C and MF settings.
It must have been knocked into that position when handling the camera. I put it back to AF.S and it was fine.

Not sure if it will help you but might be worth checking if you haven;t already done so.

Well, it is not squeaking anymore and it was not the AF lever as that was the first thing I checked.

We'll see how it holds up. Over at DPreview a Nikon user had a similar problem with an SWM lens a few years back and it was the micromotor failing.