brf:"Try a touch of thread locker (Loctite Blue) on the binding post threads."
I think that is obviously a terrible suggestion that is offered here you do not want to use automotive repair materials on your Music Reproduction System materials such as Loctite cannot possibly be good for your sensitive electrical connections if you're terminals are working themselves loose I would humbly suggest they be replaced with high quality audiophile grade connectors that will not be regularly subject to such outright failure mode.
I think that is obviously a terrible suggestion that is offered here you do not want to use automotive repair materials on your Music Reproduction System materials such as Loctite cannot possibly be good for your sensitive electrical connections if you're terminals are working themselves loose I would humbly suggest they be replaced with high quality audiophile grade connectors that will not be regularly subject to such outright failure mode.