When its plugged in the power hungry faulty card is used, so disconnect from power. My machine kept crashing not long after it would boot, which made it impossible to work on, until I found out that if you don’t have it plugged in to the power, it should boot using the integrated graphics. This is not a guaranteed permanent fix – But it has been working for me, and hopefully you experience similar results. **THIS HAS WORKED FOR ME – I HOPE IT WORKS FOR YOU, BUT I CANT GUARANTEE IT** The truth of the matter is, if you aren’t a gamer, the Integrated Intel Graphics Processor is just fine, and thankfully this chip is what allows you to get your machine up and running again. The reason Apple included two graphics processors is that the ATI Radeon is super fast, which is great for the gaming experience and video, and when you are working on spreadsheets or sending emails, the integrated Intel processor uses way less power and considerably increases battery life.
There are actually two graphics processors in these machines, the Discrete Card which is an ATI Radeon (This is the one that fails) and an Integrated one, which is an Intel Chip integrated into the motherboard. The problem stems from the Graphics Card. I paid over $3000 for it, and whilst it is 6 years old now I have grown incredibly fond of it, and I really wanted to revive it. If you are reading this, there is a good chance it is because your 2011 Macbook Pro bit the dust big time, just like mine did.