On Tue, Jun 8, 2021 at 03:55 PM, chipbee40 wrote:
It's striking that your scope had the same symptom as originally in Federico's scope.
In Store mode the 1k/4k switch is responsible for supplying the proper 1k/4k REF voltages to HOR REF, so that's a good point. As it happens Federico checked HOR REF voltages at the timing switches and they proved correct in all time/div settings (-7.91 V at 1k and -1.52 V at 4k). In 4k mode switch contact 2 is open anyway, dirty or not. In Non-Store mode the 1k/4k REF switch is not used at all.
Also taking into account the findings in the last messages I doubt a dirty 1k/4k is the fault. But I might very well be wrong here.