Please help me help my friends poorly macbook air

[lizardonsprings]

So my friends (2012 i believe) macbook air would only boot in safe mode when he gave it to me to fix.

It was running High Sierra, but wouldn't boot normally. White bar would get 2/3 of the way across then freeze.

Easy fix I think to myself, backup his files, load up my USB installer with Mojave on it and bobs your uncle.

Nope. Wouldn't boot off the USB drive (edit: to clarify, the same thing would happen as trying to boot the OS, apple logo appears and white bar gets stuck 1/2 way or so). Tried resetting the NVRAM/PRAM, SMC, all the usual stuff that help guides tell you to try when you google mac not booting.

Started running out of ideas so I thought right, I'll boot back in safe mode and check that his machine can handle Mojave by trying to boot the installer whilst in safe mode.

It works so I think right well it's not gonna do any harm if I install it whilst in safe mode.

Well it would appear I was wrong as now I can't even boot into safe mode. If I hold down shift after the chime, the apple logo appears for a moment then the machine reboots. This happens every time I hold down shift. Shit.

So yeah.. any ideas guys? Don't really want to give my mate his laptop back in even worse working order than when he gave me it haha

Thanks in advance

 

[Cory Cooper]

Hello and welcome.

Sorry it took us a bit to respond.

-You can check the exact model by entering the serial number here: Check Your Service and Support Coverage
-Were you able to safely backup his data?
-How did you create your bootable Mojave installer?
-Do you know how much free space was left?

I would try the following:
-Use Apple Diagnostics to test your Mac
-How to use safe mode on your Mac - Shift needs to be pressed before the chime and held until you see the Apple logo
-Start up from macOS Recovery

Let us know if any of that helps,

C