Hi everyone...
@Fungus, you have 4.3SP1 firmare on your scope i think. Can you do this simple test for me and send screenshots.
First connect your probes on probe calibration terminal:
1. Set your probes at 10x, and on the scope comp. 10x also (both channels DC coupled),
2. Set scope time base 500us,
3. Select for both channels RMS measurement from left vertical menu (not Per.Vrms),
4. Set Cursor Mode:Auto/ Auto Item:Quick2 (indicates Ch2 RMS, it may Quick1 select accordingly),
5. Set Ch2 10V/per.div and position -30V,
6. Set Trigger on Ch2,
7. Please take a screenshot with quickprint button,
8. Set Ch1 to AC Coupling,
9. Take another screenshot,
10. Now set Ch1 Coupling to GND and take last screenshot.
I have 4.3SP2 firmware and these are my screenshots...