Hello all,

My partner's lens recently developed a fault and I was wondering if anyone
had some suggestions as to what may be wrong and if it is worth repairing.

The body knows what focal length the zoom as (the min. aperture changes
correctly as the zoom changes) however, the body isn't able to control the
lens at all, i.e.:

* Autofocus doesn't work
* Depth of field preview doesn't work
* The lens' aperture will not change when taking a shot (when viewed with a
long shutter speed with the back open and no film)
* The body (EOS300) reports that the lens can go up to f32, when the max. is
actually f22.
* Nothing unusual is shown in the LCD display
* The body and lens has been treated very well and has not undergone any
particular bashes or scrapes
* I've taken the top off the back of the lens to check the main connector
was sound and all looks okay.
* The lens is definitely at fault as I have tested various combinations of
other lenses and Canon bodies.
* The battery has been replaced with a fresh one

Any clues as to what might be the problem? And is it worth trying to be
fixed? I fear the repair (or even attempt at repair) cost could be the same
as a 2nd hand replacement, e.g. a 'Mint condition 28-80mm Canon EF zoom lens
to fit EOS' went a few days ago for ?40 on ebay.

Many thanks for any help,

Adam.