Hi, My internal display, keyboard and trackpad are not working. I tried reseting SMC and PRAM - it's not helping. When powering up without plugged external display - internal display flashes gray color (so I can assume backlight and led are okay) - then proceeds to starting with black screen. Keyboard is working, I can turn on caps lock, but can't do anything - since black screen. Attaching external display doesn't recognize him. However when I power up with external display connected from the begining - it boots up correctly (with only external display usable), i can type my password on external keyboard, but now internal keyboard and trackpad are not working. Macbook early 2011 17", I don't know if it matters, but I should replaced battery months ago, it lives for only about an hour now. Any hints what I can do?