I've got a small update. I did figure out that none of the devices I was using was able to display the X68000's non-standard signal on any of my HDMI TV's or monitors. I found some advice online, and was able to get a picture by running the OSSC through the Framemeister. This has gotten us back to an error screen that I recognize from back when the machine was working:
View attachment 52499
Unfortunately, putting bootable disks in the system does nothing. I'm following some advice from this page, and I've gotten nowhere. I just replaced the SRAM battery, but that hasn't helped:
gamesx.com
The disk drives won't boot any bootable disks. After a hard power up, the drives make one tick, and then stop. Both drives have power, are able to eject. Holding Opt 1 or CLR at boot both don't do anything. And I can't do the more involved SRAM reset instructions because my disk drives aren't doing anything.