Home Forums Peripherals & Multimedia Peripherals Keyboard audio volume keys not working

I think "AAARGH!!!" is an understatement at this point.

#s 2 & 3 are expected, because the earliest version of OS X that can be upgraded to either Yosemite or El Cap is Snowy.

After that, I'm at a loss other than to say that it's time for you to either click on joemike's Amazon link and buy a thumb drive or

1. Wipe your OTG,
2. clone 10.6.8 onto it from your iMac,
3. boot your iMac from the clone,
4. d/l the El Cap installer from Apple onto the OTG,
5. erase the iMac with DU,
6. run the El Cap installer,

and if that doesn't get you to where you want to go...