RF 50mm f1.2 L USM lens stuck in autofocus mode (won't switch to manual)

[ianovo]

I purchased the 50mm f1.2 lens used from MPB. It was in excellent condition, and no flaws were mentioned on the website. I have been using the lens for about 4 months and have had no issues until today. When I went to switch the lens to manual focus, the camera continued searching for subjects to pull to automatically. I initially thought this was a problem with the camera's internal settings; I tried every setting to do with autofocus, disabling it, even going as far as factory resetting the camera — but nothing worked. I confirmed it to be an issue with the lens itself by putting it on two other cameras, both the same model as mine. The manual focus on my other lenses also works, its only the 50mm that is faulty. 

If anyone can help me figure out what could be causing this issue, that'd be great. If it is an issue where the lens would need to be repaired, how much could that cost and would it be worth it? 

Thank you everyone!

Ian

[FloridaDrafter]

I can only think that it is probably a faulty AF/MF switch, but I can't think of a way to check it or possibly clean it. I believe MPB has a 6 month limited warranty so you might want to check with them to see if this problem is covered.

Newton

[ianovo]

The camera still gives a response when I use the switch. Instead of turning off autofocus, the screen just stops responding to my tapping and makes the autofocus area gray instead of white. It kind of just roams. 

[Waddizzle]

I recommend contacting MPB.  The last I checked, they had a 6 month guarantee on most items that they sell.  Please note, a guarantee is not the same as a warranty.

[FloridaDrafter]

MPB's page says "Warranty". That is why I used the term 🙂 But yah, you still need to read the terms of that service.

Newton

[ebiggs1]

"I recommend contacting MPB."

Absolutely do that today. There is something going on internally in the lens. It could be expensive to fix.