Chuck,
I read again the input capacitance adjustment procedure for CH1/CH2. I have no 15pF normalizer and the high voltage calibration generator.
I can observe that when 1 MOhm input on the scope is selected, the square waveform signal delivered by the BNC cable has a visible overshoot on the rising edge. So, likely the C105 & C205 have to be adjusted too. I wonder if this overshoot could potentially contribute to the CAL02 LIMIT problem on the channel 1 & 2.
However, when calibration CAL03 routing with other channels 3 & 4 the scope also throws the LIMIT error.
Thank you,
Maxim