MacBook Pro 2012 Non Retina no Video output

[Roman78]

Hello there....

i got a MBP 2012 from a friend of mine with some Video problems. It just don't show anything internal nor external. The MacBook self is working and can be reached from the Network using Screen Sharing.

So here is what i discovered till now and i hope someone can help me a little bit. I am not that experienced in repairing such small hardware. So i got my self the schematic and the boardview of this model. It is the 820-3330A by the way and i watched some Rossmann Videos.

I measured the GPU Voltages and i discovered that PPGPUFB_S0 is a little bit to low....well it has to be 1.5 and it is 0.025V

These is what i measured:
PP3V3_S0GPU_FET 3.3V = 3.334V
PP3V3_S0GPU 3.3V = 3.331V
PP1V8_S0GPU 1.8V = 1.790V
PPGPUFB_S0 1.5V = 0.025V
PP1V05_S0GPU 1.05V = 1.048V
PPVCORE_GPU 1.0V = 0.902V

These are all PPGPUFB_S0 point. So the Memosry just don't get any power.


Here is a hi res picture of the area (~4mb)


I have to say, this laptop went to two Companies for repair. One changed the GPU and maybe the memory.

So what next to do?