"iMac error: "No bootable device -- insert boot disk and press any key"

[Minederguy]

I started up my iMac this morning, and first it was booting up nicely. But after a few seconds I realize that something was wrong: the apple sign wasn't appearing. After a while of that, I got an error message: "No bootable device -- insert boot disk and press any key". I tried unplugging the computer, waiting a little, and plugging it back in, but the same thing happened. I looked for this online and found the common solution to be holding the option/alt key, but when I tried it, it didn't work.

Please Help

-Minederguy

 

[Nermal]

I've never seen that message on a Mac; it sounds more like the sort of message produced by Windows! Do you have any external drives connected (or do you have Windows installed on your internal drive)?

 

[panzer06]

I started up my iMac this morning, and first it was booting up nicely. But after a few seconds I realize that something was wrong: the apple sign wasn't appearing. After a while of that, I got an error message: "No bootable device -- insert boot disk and press any key". I tried unplugging the computer, waiting a little, and plugging it back in, but the same thing happened. I looked for this online and found the common solution to be holding the option/alt key, but when I tried it, it didn't work.

Please Help

-Minederguy

Are you holding down the Alt key (as soon as you power it on) until the drive selection screen appears?

If holding down the ALT/Opt key doesn't bring up a list of boot drives this is indicative of a hard drive failure.

Do you hear the hard drive spin up when you turn the iMac on? Hopefully you have a backup.

Cheers,

 

[DeltaMac]

I've never seen that message on a Mac; it sounds more like the sort of message produced by Windows! Do you have any external drives connected (or do you have Windows installed on your internal drive)?

I agree.
I think that you have Windows on a boot camp partition, and your hard drive is either failing, or something has happened to the boot blocks for the Windows partition.
You COULD try booting to your Windows installer disk, and run a Windows repair.
That may help, or may prove to be a tricky fix on a partition, and you may end up messing up your OS X install.
Or, you could boot to your OS X recovery partition (Restart, while holding Command + R). Repair your hard drive using the Disk Utility. That may help.
Or, you may find out that the hard drive isn't repairable. And, the answer will be to replace the hard drive. If you need to back up your Windows partition, you'll need to do that with something like WinClone, etc. Good luck!

 

[Minederguy]

Thanks!

Even though I tried holding down the option/alt key before (and nothing happened), I tried it again and it worked!

Thanks!

 

[SaSaSushi]

Even though I tried holding down the option/alt key before (and nothing happened), I tried it again and it worked!

I'm not sure if this was your problem but you don't press and hold the keys at power up but rather right after you hear the startup chime.

 

[panzer06]

Even though I tried holding down the option/alt key before (and nothing happened), I tried it again and it worked!

Thanks!

Good to hear you're all set. Please edit the original post and click Go Advanced and change the prefix to Resolved.

Have a great day!

 

[Alesc]

"No bootable device -- insert boot disk and press any key"

My iMac displays this message when I try to boot on Windows with an USB key attached to the machine.