I purchased a Sharp AQUOS model # LC - 70LE732U, serial #104823170. it's a black screen, with the power/arrow light below the word Sharp at the bottom is flashing. 5 successive white flashes, then a pause, then 2 white flashes, then a pause, then back to 5 flash sequence.
when I manually push the power button on the right side of the TV, the power/arrow light will stay lit up in white for several seconds, then switch to the 5-2 flashing sequence.
Similar problem and I just bought mine in April. 2 flashes and 3 quick flashes. LC-70LLE734U stays on briefly and then shuts off. Did you find out the problem?