Sigma 170-500 Wierd focus issue

[Naeemurrehman]

I have recently bought used 170-500mm and upon testing a strange issue is faced. I own 18-55, 10-22, 17-50, 50, 75-300 and never faced any focusing issue with them on my 70D since past 6 years.

170-500mm works well with maunal focus and autofocus is somewhat ok through live view at night when pointing towards light source like bulbs or illuminated objects. Autofocus do not work with view finder and live view autofocus also not works in daylight as well.

Seeking help by the experts on how to get these issues resolved.

Thanks in advance for assistance.

 

[RAZKY]

I have recently bought used 170-500mm and upon testing a strange issue is faced. I own 18-55, 10-22, 17-50, 50, 75-300 and never faced any focusing issue with them on my 70D since past 6 years.
170-500mm works well with manual focus and autofocus is somewhat ok through live view at night when pointing towards light source like bulbs or illuminated objects. Autofocus does not work with view finder and live view autofocus also not works in daylight as well.
Seeking help by the experts on how to get these issues resolved.
Thanks in advance for assistance.

Hopefully you were wise enough to ensure a return policy. If you're stuck with it, contact Sigma.