Dell Inspiron 7720 :: Start Up Black Screen No Boot

Dell Inspiron 7720 (17R SE) approx 2 years old, just started having problems about a week ago when turning on the computer. LEDs flash and dell quickset buttons light up; but then process just dies, screen is black and only the LEDs by the power symbol and on power buttons are lit, never reaches the Dell logo screen, no fan sounds or anything.

At first, hitting the power button to turn off then back on and the second time the boot process would work. Then it failed to do that, so I had to remove the battery, pull the power cord and hold the power button down for 30 sec's, and then it would boot normal. Now even that does not work, just have to keep powering down and re-powering and after a random number of times, 10-30 it finally boots normal, every once in while it will work first try. It seems to be getting worse. 

I have used the Dell Diagnostic on boot (though it took many tries to get into the ePSA, that did not detect any problems. When I use the Dell Support Advanced, no problems detected, and I specifically rand the Motherboard (which included CMOS test) and those did not find any problems.

If I put the computer in sleep, it comes back fine. It is only when I shut down, laptop just will not boot until I hit power on (fail) / power off repeatedly until finally, as if by luck it works fine.