Power supplies can be a tricky thing since they can be supplying multiple voltages to different circuits and some voltages can go out while others remain.
I don't believe there is a dedicated power bus for the front panel on an HR2X.
So, where does the front panel get its power source from? I'm just learning about the power supplies and I can't see where the power source for that front panel comes from other than the PS. I do know that each of the three PSs I've replaced in HR-24-500s supplied the power to the front panel, which wouldn't light up in any of the three.
I'm going out on a limb there and may get corrected in short order. I'm going largely on what I have seen on other consumer electronics with control panels made up of switches, LEDs and perhaps a mini display tube like VCRs, DVD players, CD players and the like. I've never ripped into an HR2X.
Perhaps one of our "first look" experts will set me straight. I learn new stuff all the time. Most of what I learn is that I know less than I thought.
I do know that the 20-700s have a PS that is integrated into the motherboard. If I'm wrong about that, somebody should correct me.
Yeah, I'd like to see someone more tech-savvy than I am step in here and help you sort out your problem. We'd both learn from that.