Electronic video instruments are custom devices developed during the 1970s and 1980s that were used to make video art and other time-based media works. The devices include synthesizers, colorizers, keyers, sequencers, video capture devices, computer interfaces, and oscillators, to name a few. They may be modified commercial devices or machines built from scratch. The presentation will consider theories, guidelines, and practices within instrument conservation, industrial conservation, and time-based media conservation that are relevant to the conservation of machines. A central question is whether the machines can and should continue to be 'worked' after they are collected. Also, the presentation will look at user and institutional efforts to save the video instruments and at new instruments being developed for artists' use.