So my 500GB ST3500320AS SD15 firmware failed today. (it was a storage drive and not an OS drive) Doing some research on the drive I've come across this wonderful thread! I was curious how I can tell if the drive is experiencing the BUSY error. The drive is not recognized by the BIOS, the scan function of the Seagate firmware utility "Detected 0 devices", and the Seatools post the same message. i do not believe I hear/feel the drive spinning, but I can faintly hear, and feel, a electronic buzz noise that buzzes every 1-2 seconds for a few minutes and then stops. I am assuming the motor of the drive has failed, but unsure if this is a symptom of the BUSY error. I'm planning on trying the RS-232 fix, but not getting my hopes too high. Am I correct in this assumption?