Canon EF-100-300 F4.5-5.6 USM cause ERR 99

[eos-rob-uk]

I have a Canon 350D, My Canon EF 100-300 USM i got from ebay (there's your problem i hear you all say) Err 99's on me every other shot or so if set to F8 or around at 250/s or above. I have tried cleaning the contacts with no luck. all fine with other lens.

sometimes you can hear the aperture blades move and then err 99.

Funnily enough it works perfect with camera upside down but as soon as you get close to the correct way up it ERR 99's works a lot better set to F5.6 -or 6.3

any thoughts people, or is it time to buy a new one any thoughts on a zoom to replace this which i can afford i.e. under £300. UK. the lens gives good pictures at most settings so i would be happy with another 100-300 EF

RoB B

[Tom W]

Sounds like some physical damage inside the lens. Still, try to clean off the electrical contacts real well to make sure that it's getting a good connection with the camera.

Also, check that the mount isn't loose.

[cfcRebel]

I had two EF100-300 but sold one recently. They both work fine on my 300D.