MacBook Air grey screen of death

[leeuk321]

Hi all, my niece's 2012 MacBook Air has gone as dead a dodo. When powering on, after 2 seconds the startup-chime sounds, followed immediately by a grey screen, then nothing. It just stays on the grey screen indefinitely.

I've tried resetting NVRAM, resetting the SMC, going in to recovery mode, booting from USB, using a USB keyboard, but nothing has any effect whatsoever. What I mean is: it's as if I'm not even pressing any buttons. The NVRAM reset doesn't make the startup sound come on, and none of the recovery mode combinations actually take me into recovery mode. The battery seems fine (stays on without power), and the screen automatically dims when the lid is closed, as it should. I can hear the hard drive spinning, but I think that even if that was dead I should be able to do something on startup.

If anyone's got any suggestions or advice it'd be much appreciated!

 

[Audit13]

The Air 2012 would not have a mechanical hard drive. What you're hearing is probably the cooling fan.

Have you tried connecting the Air to an external monitor?

 

[leeuk321]

The Air 2012 would not have a mechanical hard drive. What you're hearing is probably the cooling fan.

Have you tried connecting the Air to an external monitor?

Thanks for your reply, much appreciated, and of course - yes that'll be the sound of the fan (wasn't thinking there!). I tried connecting it to a monitor but nothing shows on the monitor, not even a grey screen.

I can't get my head around it. In one way it seems as though there's some fundamental hardware issue that's completely lobotomised the laptop, preventing even it's most core functions of going in to recovery mode, booting from USB etc; but in another way, it still charges, holds power, registers if the lid is closed and dims the screen, and displays a charge symbol on the screen if it's out of power.