[DaftZomb]

I was halfway sleepwalking and stepped on my HD600's, not hard and there's no visible damage. Now the left ear doesn't work. I checked the cable to make sure it wasn't disconnected. Could I have killed the driver somehow?

 

[Bern2]

  I was halfway sleepwalking and stepped on my HD600's, not hard and there's no visible damage. Now the left ear doesn't work. I checked the cable to make sure it wasn't disconnected. Could I have killed the driver somehow?

I would disconnect the cable...re-connect....and if the left side is still out....disconnect and swap the leads and recheck to make sure it's not the cable.
 
I doubt you killed the driver.
 
Bern

 

[CaveManta]

Yeah, the driver should be just fine. It's well-protected inside of that grille. If anything, maybe a solder joint got ripped apart.
 
The cable doesn't feel "wiggly" now when it's plugged in, does it?