Hey guys. Today I went to use my 300mm with the TC14E II and it wouldn't focus at first. Set to autofocus everytime I tried to focus the focus ring would jolt back and forth (which is odd because its the AF-S model, so it focuses internally). And in manual focus, I could turn the ring both ways and it wouldn't focus. I also tried it without the extender and yielded the same results. But then when I tried autofocusing on something close-up and just gradually increased the focus length it started working.

Any idea what this could be? Would it be the lens or the camera? I did have a mishap about a month ago where I dropped the lens about 4 feet onto carpet, but it has worked fine since then, up until now. I've never had this happen before, and hopefully it wont happen again. But I wanted to see if anyone else had this problem before, or if there were any ideas on what it could be.


Hopefully I described the issue properly, any help would be appreciated.

Thanks
Chris

I get a similar focus related issue, always on this lens, and cleaning the contact pins always cures it.

Now yours has been dropped, so there is a chance that there is something dislodged inside, but you can clean the contacts for free, so has to be worth a try.

I did ask on here recently about deoxit, as I thought it may be a permanent cure, but was advised to stick to using a pencil eraser.

I hope it is this simple

I'm no electrical whiz and I read the great De-Oxit debates with interest. Finally decided to try the stuff - both the cleaner and the protectant.

A little over 18 months later and I've not had a teleconverter glitch since. I'm cleaning /treating at 6 month intervals. Also using the stuff on other electronic gadgets now, too; VHF radio, GPS, etc. The stuff has made me a believer.

I feel like a Billy Mays infomercial

Gaylon Holmes wrote:
I'm no electrical whiz and I read the great De-Oxit debates with interest. Finally decided to try the stuff - both the cleaner and the protectant.

A little over 18 months later and I've not had a teleconverter glitch since. I'm cleaning /treating at 6 month intervals. Also using the stuff on other electronic gadgets now, too; VHF radio, GPS, etc. The stuff has made me a believer.

I feel like a Billy Mays infomercial


You feel dead? Anyway, deoxit works well, but can be hell on the environment. The eraser trick is much cheaper, easier, and better for the air we all breathe.