Totally bricked MacBook Pro 2011 A1286 - No recovery. What can I do?
The MacBook Pro in question is one of the infameous AMD Radeon 6750M GPU-equipped 2011 models. Apple set up a (free) repair program which ended in 2016.

Obviously the dGPU of this Mac died later and the dGPU/Mainboard weren't properly replaced. Instead an Apple certified? technician desoldered some resistors on the mainboard to disable the dGPU.

To get it working with the Intel-GPU nonetheless (= a monitor image) a special NVRAM parameter has to be set.



After resetting the NVRAM (and the SMC) this parameter was deleted which resulted in a black screen.

To get things working again the following was done:


Removing the partioned but empty HDD
Attaching the HDD to another Mac (external casing or USB-SATA cable). The 2nd Mac has to be capable of booting to a respective system (e.g. High Sierra, which is the last macOS for the early 2011 MBPs)
Install High Sierra on the external drive and boot to it
Configure ssh access (and Remote Desktop) in System Preferences > Sharing
Configure a network interface with an IP in the same IP-network as the working Mac
Detach the external drive and mount it in the MacBook Pro
Boot the MacBook Pro (and the working Mac) normally
ssh from the working Mac to the MacBook Pro
Enter: sudo nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00
Enter: sudo reboot or sudo shutdown -r now to reboot the MacBook Pro
Success!


If the HDD would have had a properly working system one could have omitted installing a new system.

These instructions helped a lot: Disable MacBook Pro Dedicated GPU

Installing and configuring MacBook Pro dGPU Disabler (as stated in the instructions) won't work, because the dedicated GPU wasn't recognized – as menitoned: the GPU was disabled in an incompetent manner previously.