MacBook Air not booting, Boot loader not available, Internet recovery not available Recently I tried to factory reset my Mid 2012 MacBook Air. In order to do that:


I booted into Recovery mode with Command + R.
Then navigated to Disk utility and Erased Macintosh HD. 
Then I restarted the Mac and booted into Recovery mode again (Command + R). Now clicked on Reinstall macOS.
It asked me to log in with Apple ID. I logged in with my Apple ID. (Before resetting, MacBook is running OS X El Capitan, and logged in with my friend's Apple ID).
After logging in, it shows an error: This Item is Temporarily Unavailable.
I tried to install via Internet Recovery Mode (Command + Option + R). But not able to enter Internet recovery mode.

I also created a bootable USB drive and tried to install macOS High Sierra. Tried to open boot options by holding Option key while starting the Mac. But still boot option was not available.
I really ran out of options, so I followed the procedure outlined in the link, which involves simply making a bootable USB drive and restoring it to Macintosh HD.:


https://www.siliconsquad.com/how-to-fix-macbook-error-this-item-is-temporarily-unavailable/

Then I tried to boot again, got prohibitory symbol.
Then tried to boot into recovery mode, but unable to boot into recovery or to macOS.




Now, I do not have any other option to fix my Mac. Please advice on how can I fix this. I'm in desperate need to fix this.

I tried all the above using an external USB keyboard as well.

Updated:

I even tried to clear NVRAM with Option + Command + P + R. but not luck at all.

Looks like most of the key combinations are not working while booting.
I think I had one such MacBook Air. It was permanently resolved by replacing the LCD assembly at AASP as the warranty was active - it did essentially qualify for DOA (wtf? - still do not know the possible answer to that)

Workaround was to get the system in the target mode (T at startup and connect with a Thunderbolt cable to some other Mac) and install the MacOS from a good source.
ASD may help to point the finger to the dead part in need of replacement.