If you use a power strip and notice that sometimes the Pi comes up with no monitor there is a simple fix.
The problem is that the Pi, during boot queries the monitor for it's specifications and if the monitor is slow
to initialize on power up, it will not respond when the Pi asks. This leads the Pi to think it is supposed to
be headless and you get no command prompt or GUI. In the file /boot/config.txt you can add the following
two lines to fix this problem:
# Add an 8 second delay to insure the monitor is ready
8 Seconds should be enough of a boot delay to allow the slowest montiors to become ready after power is applied.