Focus problem with SEL200600G on 7RM4A camera

[BOSTONREVERE]

I have recently had an intermittent issue with my 7RM4 camera using the SEL200600G telephoto.  The lens will autofocus no problem but the manual focus ring intermittently stops working.  Sometimes if I rotate it back and forth a few times it starts working again- other times I have to power off the camera, remove and reattach the lens and it sometimes works.  

Has anyone had any experience with this issue?   I am thinking about trying to replace the MF sensor assembly- found a repair guide online and it looks doable but not sure if this part is the issue?

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[Jeffreykmd]

Make sure you have updated your lens to the latest firmware. Also check your switches on the side of your lens to make sure they are in the appropriate settings before taking your lens apart.

[Cameratose]

On 5/25/2025 at 7:42 PM, BOSTONREVERE said:

I have recently had an intermittent issue with my 7RM4 camera using the SEL200600G telephoto.  The lens will autofocus no problem but the manual focus ring intermittently stops working.  Sometimes if I rotate it back and forth a few times it starts working again- other times I have to power off the camera, remove and reattach the lens and it sometimes works.  

Has anyone had any experience with this issue?   I am thinking about trying to replace the MF sensor assembly- found a repair guide online and it looks doable but not sure if this part is the issue?

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I doubt anyone on this forum will know the answer to your question. You'd probably be best served by contacting a repair shop. Typically when a lens is suffering what appears to be intermittent failures, it has to do with a ribbon cable such as that in your diagram. However, it's always best to start simple: Have you cleaned all of the contacts on both the lens and the camera? I'd start there and see it there is any improvement. 

[BOSTONREVERE]

UPDATE- i found a OEM repair guide online for this lens that helped me disassemble (not as bad as i thought).  The MF sensor assembly had a bunch of dust in and around it- not sure but it might be an optical sensor that detects the MF focus ring.  I replaced the sensor to be safe and the manual focus seems to be working reliably now.  Lots of ribbon cables to disconnect and reconnect but otherwise very easy.

[BOSTONREVERE]

On 5/26/2025 at 2:10 PM, Jeffreykmd said:

Make sure you have updated your lens to the latest firmware. Also check your switches on the side of your lens to make sure they are in the appropriate settings before taking your lens apart.

Thanks also did this and it did not help- the sensor in the lens had to be at minimum cleaned but i replaced it while i was in there.