On Fri, Nov 1, 2019 at 11:48 PM, DaveH52 wrote:
That is something to consider. Possibly an "inadvertent" trigger from somewhere? In these pictures I am not feeding any signals to the scope. Nothing whatsoever going in. So are you thinking that there might be a problem with the trigger circuitry? If it is triggering, it is doing so from a source within the instrument. So maybe from the "LINE" trigger pick off? And it must be something which does not light the TRIGGER LED when this happens. When I do feed a signal, I get the same sort of reaction on the resulting waveform(s). I will check the trigger circuitry, per the manual. Who knows, I might find something that I did not think of. I appreciate your reply and the advice.