I have tried 3 keyboards and every one does not get power until after OS X starts it's boot sequence, it seem the USB bus is not getting power until about a minute after startup. I am therefore unable to launch diagnostics, reset NVRAM, PRAM and all the other good stuff I need at present because my SSD is dying and I'd like to upgrade it's firmware

Any ideas?


Plug out the iMac (from power) for 15+ seconds to reset SMC.

  • thanks for the suggestion, I should have mentioned that I tried that already Apr 3 '15 at 21:59
  • Does holding the alt key work when starting? Maybe a firmware password is enabled and that's why PRAM reset doesn't work. Also try all USB ports and plugging in nothing but the keyboard. Apr 3 '15 at 22:01
  • keyboard is the only thing there, I could try to disable the camera and bluetooth but then my mouse won't work and I'm screwed. Otherwise I'll maybe buy a powered hub and see if that helps me. Nothing works on the keyboard pre gray screen so no boot combinations Apr 3 '15 at 22:08
  • Hm, very strange. For your SSD upgrade in the mean time. You can also select your boot device in system preferences > startup volume Apr 3 '15 at 22:12
  • yes. I guess I could burn the ssd firmware boot onto the 1TB HD, the remains of my failing fusion drive but how do I get back? I'm booting from a thunderbolt Seagate goflex at present which is ok... thinks out loud - I'll build the SSD firmware boot onto a SATA via the goflex on my MBP and then use the goflex to boot the iMac..... Apr 3 '15 at 22:25

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