My 200-600 lens has a problem that I've read can be fixed by replacing the zoom position potentiometer. The specific failure is that the lens won't focus past 300 mm, and occurs when the camera comes out of standby. The problem occurs with both of my cameras, and I've discovered a workaround that requires that the camera be turned off, then on again with the lens set to 300mm or so. By pressing on the shutter button while zooming out to 600mm, focus at the longer focal length is restored. This is repeatable.

I do not wish to spend about $600 to have the zoom position potentiometer replaced at Precision. Since this seems to be a common occurrence with this lens, Sony should shoulder some of the blame. Has anyone successfully appealed to get this problem fixed at no charge? Also, is the potentiometer on the main PC board assembly for the lens? I think this is the part number: 5-005-640-01

I don't think so.

Honesty, this is the first time I've ever heard of this problem. I would think that if it were widespread people would be talking about it more. Do you have any links we can check out? Those of us with 200-600 lenses are now officially concerned. 

Also, that was a bot you responded to. One if the worst things about this forum, every first post get recommended to Amazon!  

When my lens is working, it functions very well.  When the camera goes into power save and comes out again with press of the shutter button, it frequently won't refocus at 600mm. It takes a specific set of conditions to reproduce the problem. FWIW I don't use any filters.

Mine is not an isolated incident. There are lots of pointers online, but many mention the symptoms (won't focus at 600mm, or beyond 300mm or so) and don't directly mention a faulty potentiometer. Many mention intermittency. When I first had the issue, it seemed to only be with my A7RV so I thought it was similar to the infamous compatibility issues between A7RIV and 200-600. Sometimes turning the camera off and back on again "fixed" it immediately for me, sometimes, releasing the lens and reattaching it seemed to fix it, sometimes cleaning the contacts seemed to fix it. All of these, of course, require that the camera be turned off. While the problem seemed to start with the A7RV, it later began occurring when the lens was mounted on my a7iii. It took me awhile to realize the problem repeatedly occurred after my cameras came out of power save. It would focus at 300 mm or so, but not any longer focal length. When I chatted with Sony, I got no satisfaction, just the suggestion to send it to Precision in CT... at a minimum cost of about $550 plus shipping and insurance.

 

Here are just a few pointers:

This one alludes to the problem: https://www.fredmiranda.com/forum/topic/1835471/

This one mentions it farther down in the thread: https://www.dpreview.com/forums/thread/4738493

 

Edited January 26Jan 26 by Austin Susan

Thanks. Scary. Yeah, Sony's CS stinks. Not the first time I've heard complaints about it. I bought my A1 from Panamoz. Yes, it's grey-market, but they provide a 3-year no-exceptions warranty around the world, far better than Sony's 1 year. If they can't fix it, they replace it. Plus it saved me $1700 US. Not everything they sell is less expensive, but I always check before I buy. 

I just looked at the 200-600 and it is currently $1,623.60 US, including shipping and the 3-year warranty, which is about $475 less than it would cost me here. Note that their prices do fluctuate some I think due to exchange rates. Might be worth a look if you decide to replace the lens.    

Good luck and please let us know the outcome. 

I have a similar problem with my 200–600 on my 7rm4a. The lens will auto focus no problem manual focus intermittently works.  If I power off remove the lens and put it back on it fixes the issue or if I move the focus ring back-and-forth a lot it will most of the time fix the issue.  Does this sound like the potentiometer?  Are there any guides online to replace this part?

This lens isssue is common in many digital lenses wher a slip ring type potentiometer is used.

These are formed around the barrel using plastic conductive curved plastic with carbon impregnated resitive strips.

The wiper contatcts sprain and fail leaving the potentiometer open circuit! the only solution is replacement. I know this because im a lens tech from the broadcast camera days.

Thanks, joe90.

 

Sony won on this issue: I bought the 300mm f/2.8 lens, and my 200-600 sits unused. It chaps me that Sony profits on their own issue.

I'm sad, regardless, that the shop where I sent my lens was unable to reproduce the problem. They didn't want to replace the part without being able to verify that the lens was fixed... so I'm out $100 in back and forth postage and my lens is still not working properly.

I would be contacting Sony direct.

Richard A, if you're replying to me, I've already gone back and forth with Sony at least 10 times, only to be quoted the warranty terms and told my lens was out of warranty. Of course, they then refer me to Precision for repair.

Oh ok. Fair enough. I haven't heard a lot of good things about Precision but if they cannot reproduce the fault then that is not really their fault I guess. I'm not in your country so I can't really help unfortunately.