Please help, stuck focus ring

I recently sold a Pentax K1000 on eBay. When I last used it (about two weeks prior to sale) the camera worked perfectly. However, when the buyer received the camera and 50mm lens he said that the focus ring won't move. How could something like that happen so fast? What can be done to fix the lens, if anything? Thank you for any and all help!

Well, sometimes inexperience of users can cause a problem and i would check one long shot first. And that is that he really does mean the focusing ring and not the aperture (f stop) ring. If the latter, and it happened to be an A series lens then it won't move off the A setting unless the small button on the ring is depressed.

I know it's a long shot indeed, but crazier things have been the cause of a problem.

If the lens has stopped working it's more likely due to physical damage than anything else. If the packaging was OK then the buyer might have done something that you are not aware of, but there's no way of knowing.

If the worst comes to the worst, I would ask for the lens or maybe the camera as well to be returned so I could have a look and either replace the lens or provide a refund.

It would really help to know precisely what 50mm lens it is

It is a Pentax 50mm f/2 SMC. Any help or advice would be appreciated!

He has stated that he can turn the aperature ring so I don't think it's that. (It was actually one of my first thoughts too) I know that it was packaged appropriately, so I doubt damage in transit.

The only thing you can do is ask him to return the goods for examination and repair/replacement/refund at your choice or just deduct the value of the lens and give a partial refund.

It's sensible to make sure you get the same lens back that you sent...

I know you may lose a little money on the deal, but good customer service will pay dividends in the end.

yep so true.
It may be dumb luck that it failed after you sold it.
it may be rough handling, but the post office.
it may be the guy who bought it broke it.

Any way you cut it, it may boil down to "What is your reputation worth vs. what was the camera worth.

Sigh. The guy is being so cooperative too, I really hoped that there might be a way he could fix it on his end and make us both happy. But thank you for your advice!

Actually, I was on the receiving end of a similar incident just today: I had received a Pentax MX with a SMC-M 50mm f:1.7 lens and, after a few trials, I realized I couldn't turn the focus ring past the 2 meters distance. This is how I discovered this topic, by the way...

Anyway, before doing anything drastic, I tried gently shaking the lens in every directions - and to my greatest surprise, it worked. I suspect some sort of debris got stuck in the mechanism during transportation... Not a very good sign for the durability of the lens, I guess, but it seems to be perfectly fine now. Worth a try.

Of course you're disappointed but the lens is around 25 years old!

Disappointed? Not really: surprised, since it's the first time I had this kind of problem. And I'm not laying any blame on the seller: that probably never happened to him, either. Moreover, by the look of it and despite that little happening, this lens still has quite a few more years in it.

However, I must say I'd have been a lot more disappointed if my 50mm f:1.4 lens had been the victim!

I've had this happen in Pentax lenses-and the problem seems to go away, permanently. No real idea, sorry.