Nikkor 35-70 F2.8 - Not focusing at 35mm

My 35-70 F2.8 D Nikkor lens does not auto-focus when set to 35mm, but does focus at focal lengths beyond about 40mm.  My cameras respond as if the lens were a manual focus lens (the auto-focus motor does not engage).  Any idea what might be causing the problem?  I tried cleaning the electrical contacts on the back of the lens to no effect.  I cannot see spending over $200 US to fix a lens which is worth less than $500.  Any suggestions would be appreciated.

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bmw