iMac 2009 doesn't register key combinations and always ends up on windows 'No boot device found'

[camerong123]

Hi there,

I have acquired some iMacs from 2009 which have had windows 7 put on them for whatever reason. I'm trying to get macOS back on them but whenever I boot them up (current OS is corrupted btw) I get a blank grey screen followed by the PC style 'No boot device available press enter to try' Here's the weird bit though, no matter what keys I press (Alt to get to boot menu, Cmd+r, Cmd+alt+p+r) I still end up on that screen with out any sign it's registered them. Even when I press enter to try again nothing happens. The light on the mouse comes on and once I've booted into Ubuntu off a DVD, the keyboard works fine so the USB ports aren't bad. That's the other thing, it will boot off a DVD (I've tried windows and Ubuntu which both work) but I don't have a mac DVD and as I can't enter the boot menu I can't select a USB drive and it doesn't detect it. It seems like the firmware has been tampered with as even with the HDD completely erased, the same things happen. I mean to make a snow leopard DVD but haven't got any spare atm. Has anyone got any solutions? Thanks

 

[ApfelKuchen]

Hi there,

I have acquired some iMacs from 2009 which have had windows 7 put on them for whatever reason. I'm trying to get macOS back on them but whenever I boot them up (current OS is corrupted btw) I get a blank grey screen followed by the PC style 'No boot device available press enter to try' Here's the weird bit though, no matter what keys I press (Alt to get to boot menu, Cmd+r, Cmd+alt+p+r) I still end up on that screen with out any sign it's registered them. Even when I press enter to try again nothing happens. The light on the mouse comes on and once I've booted into Ubuntu off a DVD, the keyboard works fine so the USB ports aren't bad. That's the other thing, it will boot off a DVD (I've tried windows and Ubuntu which both work) but I don't have a mac DVD and as I can't enter the boot menu I can't select a USB drive and it doesn't detect it. It seems like the firmware has been tampered with as even with the HDD completely erased, the same things happen. I mean to make a snow leopard DVD but haven't got any spare atm. Has anyone got any solutions? Thanks

You are going to have to boot from a Snow Leopard DVD or a USB drive with a bootable OS X installer https://support.apple.com/HT201372. Macs that old do not support booting to the recovery system from the EFI firmware.

 

[camerong123]

Ok that explains not getting into recovery mode, but why wouldn't the Alt key work?

 

[Nguyen Duc Hieu]

Ok that explains not getting into recovery mode, but why wouldn't the Alt key work?

Wrong key combination, I guess.
Clearing PRAM: (Better do it with no SSD/HDD attached.)
On Apple keyboard: Command + Option + P + R
On Windows keyboard: Windows + Alt + P + R.

You have to do it very fast. And use a simple membrant USB keyboard. Mechanical keyboard are slow to be recognized.

If the above does work, try clear SMC, too.