Not BootingI have this problem with two Macbook Pros (2011 & 2012 models). I've replaced the RAM, battery, harddrive & power supply. The...
Answer to: Why does my MacBook Pro turn on and then off again?I found a fix for my new Macbook pro that had these symptoms. If I booted the laptop while holding down the shift key OSX started and worked normally. If I let go of the shift key the laptop would perform a forced reboot. I opened up the laptop and disconnected the internal keyboard from the motherboard and everything worked normally. I now use my laptop with an external blue-tooth keyboard as Apple say it will cost £850 to replace the keyboard membrane as a permanent fit.