MBP wont boot, black screen, lights working, mag strip green.

The dual graphics GPU is a well known issue on this model.

You will probably have to install this on another Mac by pulling your hard drive and hooking it up to another using an USB to SATA adapter.

I’ve saved about twenty 2011 15” MBP using this gem, it’s also free ;-)

To turn off the dual graphics capability of the GPU, install gfxCardStatus for Mac

Download  https://gfx.io

This will disable GPU switching and force the MacBook Pro to use the higher powered discrete graphics card rather than the integrated GPU.

1. Go to the  Apple menu and choose “System Preferences” and then go to “Energy” control panel
2. Uncheck the box next to “Automatic graphics switching”
3. Note the text which states this may decrease battery life on the MacBook Pro “When automatic switching is disabled, your computer will always use high-performance graphics. This may decrease battery life.” – if you are not OK with that do not disable this option
4. Close out of System Preferences
5. You can always return to the Energy preference panel to re-enable the GPU switching feature if desired.
6. For MacBook Pro users who want to manually control their GPU use, you can use a third party tool like GFXCardStatus which has been around for quite some time and still works on most modern MacBook Pro models as well.
7. https://gfx.io/switching.html