Hi

The problem started couple of months ago with the funny noise coming from the lens trying to focus. It would "trrrrrr"ed for a couple of secs and then focused alright but last month it died completely. Now it doesn't focus and the camera says "lens not attached". I found a page about a similar problem at lensrentals.com (https://www.lensrentals.com/blog/2015/04/tearing-down-the-sony-24-70-f4-za-oss-vario-tessar/) and I tore down the lens yesterday but couldn't identify the problem, the parts I could see seemed intact. It was only after I reassembled the lens that I found out that the focusing part was moving up and down freely even when the lens was not attached to the camera. I was hoping that I could attach some videos, but they are too big to upload. I only attach the picture of the focusing part (taken from the lensrentals. I hope he doesn't mind my using it without his permission)

Here are the detailed info about the problem:

1. When I turn the camera on, it shows as if everything is alright, but a moment later, without touching anything, the F indicator goes "F- -"  and it goes on doing this in turns.

2. When looked into the lens, I can see the diaphragm opens and closes jerkily as the indicator on the screen goes between "F4" and "F- -" 

3. When unattached and tilted, the focusing part of the lens (seen in the picture) moves freely up and down (not sure if this is normal or not)

 

Anybody has had a similar, if not the same, problem?

thanks a million in advance

Yes I have exactly the same problem.

I recall the article you mention found that the focus lens had become unattached to the motor drive coil - the glue had come unstuck from the coil. Although not mentioned in great detail the fix seemed to be some epoxy 2-part resin glue applied to the area - but it was explained whether the old glue was removed first. I haven't explored into the lens yet but will do so this weekend. I hope it is a focus coil issue and nothing else (as nothing else looks to be repairable)

Yes I have the same problem with the lens. All of a sudden the lens seem to be having problems focusing and making a funny noise. We were away on vacation at time and I was getting very frustrated with it although I was able to use it.  This was the only lens I had with me so I had to use it. It became more frequent and once I just shook the camera and lens and it stopped for a bit but then started again. I have since bought another lens and have not used it. If I shake it the lens rattles a bit. Where did  you find a video to take the lens apart? Have you been able to get to fix it?

yes, I have the same problem with the lens. The moment I attach it to my camera the noise starts, right now it's not focusing at all and information tells me lens not attach. I am frustrated

For those of you who have this problem, can you still focus the lens manually?

Cor, you're brave, taking apart an expensive lens like that!

I guess it's out of warranty and the specialists are too expensive?

I have had a similar issue with this lens, after using it sporadically for about 5 years.  Intermittent grinding noise for the past few weeks and sometimes hunting to focus.  Now in the past 2 days grinding is more frequent and half the time fails to focus properly.  

When this happens, manual focus also fails at distance (near infinity).  Problem comes and goes.  Perhaps worse after an hour or more of repetitive shooting.  Possibly worse with polarizing filter in place rather than UV filter.  Still trying to figure it out but thinking I will need to send in for repair or replace it.

I has a very similar problem with a Sigma lens a few years back when the focus drive sheared and all I could hear was a grinding noise when it tried to focus. The lens was out of warranty and the cost of a repair was exorbitant.  I guess that things do break after a while. RIP dead lens.

I guess there's something to be said for using manual-focusing lenses after all.

1 hour ago, XKAES said:

I guess there's something to be said for using manual-focusing lenses after all.

Indeed, just like there's something te be said for walking rather than driving a car when trying to get from A to B.

Exactly!  You are much less likely to die in a car crash if you are walking.