I have a soft spot for the Sigma DN Art lenses. They offer great image quality, come in three versatile focal lengths (19mm, 30mm, and 60mm), and are incredibly compact. In a pancake-sized design, Sigma engineers have packed a very capable lens with excellent sharpness and pleasant rendering. I also love this series for its very common, almost charmingly typical issues. These flaws show up just slightly less often than always - and are generally very easy to fix. This time, the 19mm version (for the Panasonic/Olympus Micro 4/3 system) showed no signs of life other than some noise, and threw an error when mounted on a camera. Let's tear it down (with pleasure) and see what's going on this time.
