Re: 820-2915-B Chime, Boot to OS, Hear sounds, but No Video



When GPU is powered on, PPVCORE_GPU should drop from 1.1V to 0.9V. That is probably bad GPU....

Re: 820-2915-B Chime, Boot to OS, Hear sounds, but No Video

Thanks. I managed to disable AMD GPU on blind, and now it's works only with iGPU. Problam was probably with GPUVCORE chip regulator or with GPU.

Re: 820-2915-B Chime, Boot to OS, Hear sounds, but No Video

I don't think GPU is bad because it's booting to OS X. And if it's bad I would disable it and use it with only integrated graphics. I also tried to disable GPU and use only Intel but than backlight doesnt work. So there is definitely some other problems. If anyone have any ideas, please say. Thanks!

Hello to all. This is my first thread, and I hope someone will help me with this board. I would like to say that I'm new to logic board repairs, but I know how to measure voltage, resistance, know what is diode mode and things like that. Let's start.

I have MacBook Pro 15" 2011 without VIDEO. So it's not problem with backlight because I dont have video signal at all. PPVCORE_GPU is 0V, and it should be as I understand 1.10V when laptop is off, and 0.9V when GPU is initializied. I know it's not problem with GPU because MacBook chimes, boots to OS X, keyboard backlight is working...

Re: New Members - please post your introductions here

Hello all, I'm new to this forum. I hope i will learn something here. Thanks in advance for all help I get here.