Canon 24-105 problem

I am having trouble with my canon 24-105 F4 lens.
It works fine with IS on and iris at F4.
As soon I am closing the iris a bit, for example F4.5 and I push the shutter my picture is shifting and the photo becomes blurry
When IS is off I am able to shoot sharp pictures at F4.5 without problems
It seems the lens is not able to let the iris and the IS work together.
So I can only work with IS at F4.0, with other iris settings I have to switch of the IS
Does anyone know about this problem?
Does anyone have the service manual of this lens?

Thanks in advance.

i'm not sure that this is a lens fault, have you tried another lens ?

It sounds like the sort of fault you can get when the battery is getting a bit old and unable to supply enough current.

The service manual is unlikely to help because it won't give details of possible faults.

Yes, I tried several lenses and batteries, it only appears with this lens.
Because I am working in electronics repair, I opened the lens and noticed a capacitor, which was mounted wrong (reverse polarity).
I have checked it with several pictures of the electronic PCB and I am sure is was mounted wrong.
I ordered a new capacitor in an elecronic store and replaced this capacitor, unfortunaly with no result.
So now I am looking for the schematic diagram of the PCB of this lens, so I can check for other defects.

I had a very similar problem with my EF 24-105 F4 L (mark I). I've seen several other posts about this, too. In my case, my camera — a 5dmIII — would give me an error code if I pressed the shutter and the aperture setting wasn't wide open at f4. Someone mentioned in one of the posts that there was a part that seems to wear out over time — I want to say it was a ribbon cable.

Unfortunately, Canon doesn't support the 24-105 mark I any longer. A 3rd part repair service should be able to repair it if you want to get it serviced.

Now that I think about it, that lens only lasted me about 10 years before it broke down. Not what I would have expected from something with the L designation. To be fair, it was my most used lens, but I would say overall it was only lightly used — I'm not a pro or anything.

Sorry I don't have better news for you. I ended up getting a mirrorless body recently, and I used that as an opportunity to replace my faulty EF 24-105 with the RF 24-105. Hopefully this one fares better!

Tim

I got this lens from my brother, who has passed away last year.
I am trying to use it on my 90D, but it never worked as it should.
Could it be this lens is not suitable for the 90D?

Ger57 wrote in post #19497953
I got this lens from my brother, who has passed away last year.
I am trying to use it on my 90D, but it never worked as it should.
Could it be this lens is not suitable for the 90D?

That lens is perfectly compatible with the 90D. Since you are into electronic repair, I suggest you seek out a replacement ribbon cable or flex cable (it goes by various names) and replace it. You can get one for about $10. See https://www.ebay.com …24-105+flex+cable&_sop=12

Videos exist that show the replacement procedure. One is at https://www.youtube.co​m/watch?v=f-FmvQubSVw.

Note that depending on the vintage of the lens some people mention having a different connector so examine what you buy carefully.

Can you explain to me why the aperature is working fine when IS is off?
When the flex cable is malfunctioning I would expect it to fail as well when the IS is off.
There is also no error message.

I can send you a PDF copy of the service manual, just send me your usual email address via private mail on the forum.

It seems I can only send you a PM as soon I have placed 20 posts on this forum?
I am new on this forum, so it may take a while

Is it possible for you to contact me?

I had the exact same issue with my old EF 24-105L. The picture would shift in the viewfinder when IS was engaged. I had to use the lens with IS switched off, as it wasn't worth the cost to repair. I ended up selling the lens "as is" along with my 5D3 after I bought a Canon EOS R + RF 25-105L kit.