I have an MSO 5074 just five months old and very lightly used back in early 2022 for (successfully!) debugging a broken ESQ-1 digital synthesizer from the '80s that I restored. Pulled it out for some digital tracing on another synth project this weekend and it isn't getting signal on the display. I tried reflashing the firmware to latest official RIGOL, and Utility>System>Self Cal>Start (all cables disconnected). It consistently hangs at 3% calibration and will not progress past that. Ive also "hard" reset it using the "single" button on boot method. No dice. I am not an EE just a synth nerd who has had some luck learning my way around circuits a bit so it could very well be something really dumb.
Any help or advice would be most appreciated!