Hello
It should be kept in mind that CPU_KEY 0000 is to be placed and renamed after the installation of the RGH it can be recorded so that the device accepts an alterative Cpu Key numeral
(this does not mean that your console was clean to navigate to xbox live)
This practice facilitates mass production and the low cost of production
In the video below this step by step for you to use this GPU and reprogram it using:
XDK Recovery
In the video demonstrated step by step
I hope it helps you understand