using a magnet to wake it up
I know I'm late on the scene for this issue but I was looking for help solving the same problem as described above. I know what the issue is, however I am unable to find a permanent fix. It has nothing to do with a power related issue, there is an electromagnetic sensor on the main board that responds to the magnetic field from the speakers in the upper half of the unit. When closed, the speaker magnets trip the sensors causing it to go into sleep mode, when opened, the magnetic field is no longer present and the sensor allows the device to wake up again.
When I had this issue, I could use a simple permanent magnet and swipe it above the bottom screen and the device will function again. When closed and reopened, the device malfunctions again. I know where the issue is but using a magnet to wake it up is not a practical solution.