Lens stopped autofocusing (Canon 1D MkIIn with Canon 85mm)

All,

My Canon 85mm F1.8 no longer autofocuses on my *old* Canon 1D MkIIn.
The camera does autofocus with Canon 24-105 F4 fine. The lens (85mm)
also autofocuses fine on a friend's 7D.

Any suggestion to resolve or narrow the problem (or at least
isolate it to the camera or the lens) are greatly appreciated!

Cheers,
Alex

On 26/10/2011 6:21 a.m., alex wrote:
All,

My Canon 85mm F1.8 no longer autofocuses on my *old* Canon 1D MkIIn.
The camera does autofocus with Canon 24-105 F4 fine. The lens (85mm)
also autofocuses fine on a friend's 7D.

Any suggestion to resolve or narrow the problem (or at least
isolate it to the camera or the lens) are greatly appreciated!

Cheers,
Alex

Check and clean the contacts, perhaps try "Deoxit" (I've not used this
on cameras, but have had incredible results cleaning up other electronic
contacts, ribbon cable connector, board edge connectors etc.
I was a sceptic about this product - because it seemed expensive.