Starring: Joanna Lumley, Patrick Macnee, Gareth Hunt
The Last of the Cybernauts ...?? - S1-E3
Audio problem: During the opening scene when the cast are gathered around the piano singing "Happy Birthday" to John Steed, his voice is audible as a part of the singing from the start, but he doesn't start singing until the second line.
K is for Kill: The Tiger Awakes (1) - S2-E8
Visible crew/equipment: A Russian solder peers into a Salvation Army hall. In the shot that follows, from his point of view, there's a very obvious studio light on a tripod in shot.