!!!!! THIS AUCTION IS NOT FOR THE SALE OF A LENS !!!!!
If you have a Canon EF-S 17 - 85 mm Lens which occasionally or permanently gives an Err 99 or 01 then read on
Over time an internal flex cable which is bent and flexed each time you use the Zoom on this lens eventually weakens and snaps, this can lead to the lens not always focusing correctly on anything in automatic focus mode, and when any Aperture above the lowest available is used you get the error on the camera.
If you have a Depth of field button on your camera you can check to see if it is the flex cable for certain, select AV mode on your camera dial and then depress the shutter half way now press and hold your Depth of Field button while at the same time adjusting the aperture, you should hear some ticking noises coming from inside the lens or if you look through the eye-piece while doing this the image should get darker and lighter as you adjust the Aperture
Alternately select AV mode on your camera and if you are having autofocus issues switch to Manual focus, now select the lowest Aperture (f/4 at 17mm and f/5.6 at 85mm) and take a shot at 17mm and one at 85mm, you shouldn't get any errors on your camera, now select a higher Aperture say f/7.1 and take a shot again at 17mm and one at 85mm, if you now get an error this will confirm that the Flex Cable is broken or starting to break.
You can also check to see if the Autofocus is working by putting the Lens cap on and pressing the shutter button half way a couple of times, if you look in the focus window while doing this you should see the lens go from Infinity to Macro and back again this means the autofocus is not at fault, if it doesn't do this it may mean the USM is faulty but this is not always the case as I have had some where this happens due to the Flex Cable.
If your lens is having other symptoms I may still be able to help just send me a message and I will advise you as best I can
On top of repairing the lens all large internal dust particles will be removed and the Lens Elements Cleaned, also if your zoom ring is loose and your lens keeps extending I can also Adjust this if you require and the barrel is not too worn
Once payment is cleared I will send postage instructions to you, upon receiving your lens it will repaired the same day and posted back to you the following day First Class Recorded, if you require Next day delivery and added insurance then please select the Royal Mail Special Delivery Service option when paying through Pay-Pal
Any questions please don't hesitate to ask