MacBook doesn't start up and goes to sleep [PLEASE]
I'm having serious problem with my MacBook. Since fees days, it was going to sleep randomly as I was working on it. And I couldn't get it out of sleep, I had to force turn it off by holding the power button.
This morning it doesn't even start, I hear the "Dong", I see the grey apple, but as soon as the login screen appear it goes to sleep. If I try waking it the screen flash and goes back to sleep again.
I've already tried to reset PRAM, SMU, replace the battery, replace the ram sticks, but nothing has change. I can't go to recovery HD too, same problem.
I think it might be a defective sleep connector (temperature sensors, magnet) but I don't know how to check.
Do you have any ideas to help me ?