I recently tried to install big sur on my macbook through a bootable USB drive. Everything went well until during the install the computer auto rebooted and showed the apple logo and load bar then went blank. I guessed the system was still installing so I waited 10 hours but still a blank screen. Now I have tried to unplug the USB and restart but the computer seems to be stuck in some kind of limbo. Here are the symptoms:
- No chime when powering on
- Backlight turns on but nothing is displayed
- Fan spins
- Ignores closing laptop lid (Fan still runs and backlight on)
- No display signal (external displays say no signal)
- USB gets powered on
- Cannot boot into anything (Recovery, internet recovery, verbose mode, safe mode, usb drive)
I have tried:
- Resetting SMC
- Resetting NVRAM
- Removing battery, leaving for an hour and reconnecting.
- Replacing SSD with a working SSD from an identical macbook model. (still nothing)
- Removing and wiping SSD using another computer
- EDIT: I tried letting the computer sit with the screen blank to drain the battery as a last resort and now it will display the red low battery graphic if I press power on. But still no boot.
It seems base system is missing or corrupted. I have tried everything. What do you think?