ReadyNAS 2100 cannot boot

Symptom: Unit powers on.  At power-on, the USB light is on solid and the power led flashes.  After a few moments, the power led goes solid.  That's it.  (Network link never comes up, so I'm not able to see what it might want to report in Raidar).

I have tried several versions of the USB flash recovery and none have been successful.  I believe it just didn't like the first usb stick as it never powered itself off after any amount of time.  When I tried a different one, the unit did power itself off after ~2 minutes, but upon powering it back on, the symptoms as described earlier are still present.

Holding down the Sys button while booting doesn't help either, it just goes to the solid USB and power LEDs as if I didn't even hold it down at all.

Several of the drives were going flaky in this unit, so I had, luckily, already migrated all of the data off of here.  There's no fear of trashing any of the data, but I would like to have this unit functional again.

Edit: Odd, but after repeating the recovery a second time, the unit finally booted up correctly.  I have some other questions now, but will put those in the appropriate forum.

Any ideas?