(This is a 80 gb Hitachi HDS728080PLAT20 sold by Edge Tech DiskGo)
Had issue where I had to shut everything down via the power strip (bad, I know!). Was not getting green light when I turned on power to external disk – replaced power adapter cord – got green light. Yet disk would not spin. Tried a new enclosure – still nothing. Tried gently shaking to loosen possible stuck head. No go.