HP Surestore DAT 24×6 Autoloader Stuck in Self Test Mode

I have an HP Surestore DAT 24×6 that I acquired from a company that was disposing of old equipment they no longer needed. Anyhow, when I turn the unit on, all three LEDs’ (2 green and one orange) blink in unisen and the LCD display shows “Self Test” indefinitely. The unit is not connected to a SCSI controller just yet, but even when connected, the device is not seen during a SCSI bus scan. Has anyone seen this issue with the unit being stuck in self test mode? Is it possible the unit is defective, even though it was used before and was guaranteed to be in working order by the person who gave it to me?