5D Mark IV Err 01 24-70mm 2.8L only when changing f-stop

[adimauro]

As long as my 24-70 is at f/2.8, it works fine regardless of the other settings. But, as soon as I change the f-stop, I get the Err 01 message. Yes, I've cleaned the contacts, and, as usual, it does absolutely nothing. Is there any way to fix this, or am I stuck in f/2.8 forever?

[deebatman316]

It sounds like the flex cable in the lens has failed. Which version of the 24-70mm lens the original or the Mark II. This was a common problem with the original 24-70mm.

-Demetrius

Current Gear: EOS 5D Mark IV, EF 16-35mm F/2.8L III USM, EF 24-70mm F/2.8L II USM, EF 50 F/1.8 STM, EF 85mm F/1.8 USM, EF 70-200mm F/2.8L IS III USM, 470EX-AI & 600EX II-RT

Retired Gear: EOS 40D & Sigma 17-50mm F/2.8 EX DC OS HSM