Worth getting 24-70mm f/2.8 repaired? Power diaphragm and lens ass'y need replacing

[Snappey7]

Hi all,

I got my 24-70 checked due what i assumed were stuck aperture blades, however was advised that the power diaphragm and lens ass'y needs replacing, quotes are showing around $650-700 for repairs, i do not think its worth it as I may as well get a new lens, however spending any amount like this is not possible for me, does anyone have any advice on cheaper repair alternatives or experience DIY and the difficulty level of replacing it myself?

[Ron888]

I've fixed many lenses in the past ,learning as i went.
It's possible if you know which parts need changing,can actually buy the parts,dont need any special tools and -this is a big one- no optical testing is needed.
Most cheap lenses i've worked on are relatively easy, even with their nested zoom mechanisms.Lens elements (or usually groups of them) are fixed with screws.No shims or alignment necessary.Usually they'll have only one printed circuit board.
More expensive lenses tend to have shims for precise positioning of lens elements.Those can require the use of special optical testing tools.These lenses can also have multiple PCBs,lots of ribbon wires and complicated construction.
I'm guessing it would be easy to replace the diaphragm in your lens.Getting to it might be complicated but it should bolt right in.
Lens replacement could be a deal breaker.Do you know which once are bad?
Also let me know which exact model lens it is.I'll see what info i can find online

[ebiggs1]

I am assuming you have the ef 24-70mm f2.8L? I would not recommend a person that has no experience in lens tech and repair to try this as a first project especially if money isn't there. Most lens repair these days are sub assembly replacement and not actual repairing.You could end up with an expensive paper weight. The additional problem is if you don't notice ay further parts that are faulty. Perhaps the failure of something else caused the problem you are seeing. You are not likely to know or see or even that it happens.

On the other hand if you have the time and the money to lose by all means jump right in and good luck.

[ebiggs1]

" i do not think its worth it as I may as well get a new lens, ..."

That is something you have to decide but it is smart to find out how much a good working used lens is going for. You certainly don't want to spend anywhere near or close to that amount. Whether you do the repair or have it done but keep in mind that repaired correctly your lens will be as good as it ever was. It's a great lens.

[Ron888]

I had a quick look on youtube.There are several videos where people are working on 24-70 lenses.
The one i watched was for the EF24-70/ 2.8L II where he was replacing the diaphragm.It was rather complex!

[March411]

This job is best left to a professional unless you are really OK with ebiggs1 thoughts on it becoming an expensive paper weight. It's a nice lens, personally I wouldn't try. I would however most likely would look at the cost for repair. Same lens in decent shape bought used would be at least a $1000 lens if you were going to replace it like for like, probably more for one in excellent shape.

[Tintype_18]

Could it be sold to a repair facility for parts? Had a P&S camera that wouldn't focus. Paid $85 but would cost $100 to fix.

[Ron888]

This is a good option. It's common to see lenses selling for parts on ebay