Cannot boot from USB on 2009 MBP

[RRmalvado]

I am trying to clean install Mountain Lion on a Mid-2009 MBP (http://www.everymac.com/systems/app...3-mid-2009-sd-firewire-800-unibody-specs.html)

However when I attempt to boot from USB by holding down the Option button I only see the Macintosh HD and the Recovery partition for Lion. If I unplug and replug in the USB drive the computer freezes, as in I cannot select any drive to boot from using the trackpad or the keyboard. If I unplug again I get the little poof cloud, sorta like when removing a shortcut from the Dock.

I have tried SMC (http://support.apple.com/kb/HT3964) and NVRAM/PRAM (http://support.apple.com/kb/HT1379) and rebuilding the USB key using Lion Diskmaker.

With the same USB drive I updated my MBA to Mountain Lion early this afternoon.

Any thoughts?

Thanks.

 

[fleawannabe]

I had problem like this as well, try this. Hold option like normal, select your regular Mac HD, then before you log in restart the Mac. Now hold option again like you did the first time and your external SHOULD be there. Good Luck.

 

[RRmalvado]

I had problem like this as well, try this. Hold option like normal, select your regular Mac HD, then before you log in restart the Mac. Now hold option again like you did the first time and your external SHOULD be there. Good Luck.

With the USB drive inserted from the beginning?

 

[fleawannabe]

With the USB drive inserted from the beginning?

Yes

 

[RRmalvado]

Yes

After restarting, it now freezes right before the Macintosh HD is fully visible looks transparent still.

I left it alone for a few minutes and then it finally loaded but the USB drive was visible for about 2 seconds and the went away in a puffy cloud.

 

[fleawannabe]

After restarting, it now freezes right before the Macintosh HD is fully visible looks transparent still.

I left it alone for a few minutes and then it finally loaded but the USB drive was visible for about 2 seconds and the went away in a puffy cloud.

Um, that's odd. Hopefully you figure it out.

 

[fleawannabe]

After restarting, it now freezes right before the Macintosh HD is fully visible looks transparent still.

I left it alone for a few minutes and then it finally loaded but the USB drive was visible for about 2 seconds and the went away in a puffy cloud.

This is pretty intensive but, could you:
1)Have a friend with a Mac Clone his hard drive to an external.
2)Reinstall his HD
3)Upload your HD from your has external to his fresh Mac
4)Hook up your Mac to his Mac and do Migration Assistant(getting your info)
5)Then have him put is info back on his from his external.

Would that work as a last resort?

 

[Mr MM]

you have to modify the plist in the bootcamp app.

you need to add support for usb boot for the model that you have, its quite simple to do that.

 

[RRmalvado]

I went in another route, I burned Mountain Lion to a DVD and installed it from that. The install went without a hitch.

Thanks everyone for your help.