I have a new-to-me DSA90604A with the latest firmware, and it passes all self-tests and self-calibrations. I've noticed that when it is displaying a steady waveform (such as its own calibrator output or a 10 MHz GPSDO), it seems to "stutter." That is, the waveform will freeze for a brief fraction of a second, then go back to continuously updating. This might also be described as "flickering." Frequently I will also see the Arm'd and Trig'd lights blink off momentarily.
I've started from the default setup, and with triggering in both the auto and triggered modes. The trigger level is set at the midpoint of the waveform, but the level seems to have no effect on the stuttering. It happens at almost any sweep speed, but seems to happen more often at faster sweep speeds. All four channels exhibit the same behavior.
This is my first 90000 series scope, and I'm admittedly still getting used to it and all of its features, but I'd like to know if what I'm seeing is normal, or if it indicates a problem somewhere.