Acorn stairlift OSG error code "O" repair workaround, no parts were required, service call diary

Fixing easy. As @Ken Flack noted in Facebook Acorn Stairlift Users Group and videos in video sites, Acorn F7 OSG error are failing or triggering without a real Over Speed condition. Several DIY guys in Maple Ridge and Vancouver BC have figured a permanent solution, or two. My diligent Internet search has not turned up a single Over Speed condition in Acorn 120, 130, Bison Bede 80, or Acorn 180 stairlifts, including CPSC product safety recalls and the UK stairlift engineers' forum. Therefore, logic militates there is no genuine function for this trigger-happy, failure-prone Acorn stairlift component.