Macbook Pro 15" Mid 2012 Efi Chip Issue or Not?

[kazer_x.x]

Hello Macrumours Forum, I recently bought a MacBook Pro Mid 2012 15 "Logic Board with an i7 2.3 Nvidia GT 650m and Intel HD 4000 Graphics, the guy who sold me the logic board told me about the full functionality and he performed the installation, I was a little curious that the macbook pro only turned on pressing the power button for five seconds and then connecting the magsafe charger, I do not pay much attention because I did not have a hard drive with the system to check that detail , when I get home the first thing I do is to perform a smc restart to turn on the mac and then the keyboard backlight does not turn on, when I opened the back cover I noticed that it was not connected to the logic board, after disassembling the logic, the first thing I saw was the EFI chip clearly intervened in the logic board, after putting everything in its place, to my surprise to check the temperature of the processors, there was no sensor or detected in the application I use, only the hard disk temperature and no fans are detected in Mac Fan Control, my question is, the real problem is the efi chip reprogrammed in that logic board, I mention all the above to the guy that I I sold the logic board, but he indicated that it could be due to my generic magsafe and probably to the power center of the mac that is failing, what do you think I'm missing? Thanks for any advice