i had the really quick green flashes too!
it happened yesterday and today!

yesterday it was during a call.. suddenly everything stopped, i checked my phone and it was flashing green really fast.. then it stopped after a couple seconds and resumed as normal

BUT today! i went to unlock my phone *double tap* and all it would do is flash green light really quick (when i say quick, i mean like.. continuous blinking) and the screen wouldnt turn on.. it would remain black (as if it was off) but blink green
i tried this for about 10 minutes... and then decided to leave it.
after about 30minutes i came back and tried, and the phone worked fine again


so i dont know whats happening.. but we need to find out what this blinking green light is
(and it is not the same as the pulsating green light for missed calls)