Chosen Solution

I have a friend’s Macbook Pro 13 inch mid 2012, i5 version with the HD 4000 iGPU. It seems that whenever the intel graphics driver is loaded in MacOS, the computer just turns off. I have tried different RAM, I’ve cleaned up the board and fan, replaced thermal paste, swapped RAM, to no avail. Even booting from internet recovery results in the MacOS installer loading up to a point, and at the point where it loads the iGPU driver (the familiar momentary flicker/change in brightness) it switches off. This happens with both connected and disconnected battery, with a known good charger. I’ve never in all my years of computer repair ever come across a defective iGPU, but I guess it must happen sometimes. Are there any known remedies for this issue, apart from a new (used) logic board?

Are you sure thats the problem? What happens when you run the onboard diagnostics? Or, even run Target Disk Mode? If they both fail then it’s time for a replacement logic board.