QUOTE(wilgo45 @ May 15 2012, 08:06 PM)

Is your system modded ?
RGH v1, 12v fan mod, serial port, and hdd mod (tapped 3.3, 5, and 12 and added 100 uF, 220 uF, and 560 uF caps - no shorts or pin bridges). It worked before the issues developed.
QUOTE(wilgo45 @ May 15 2012, 08:06 PM)

Check the power brick ... check the standby voltage ... check the power plug - look for damage or loose solder joints
Brick is good. 5VSB is stable and has proper continuity. There is no short between any of (3.3, 5, 12, 5_SB, GND).
QUOTE(wilgo45 @ May 15 2012, 08:06 PM)

Look over the Caps and the Mosfets. Check the 3.3 and 1.8 voltage regulators. Check all the input an output ports for damaged pins. Pin with power that gets grounded will do this. Especially with the USB ports
Outputs of 3.3 and 1.8 are correct. Since there isn't any short between any power and any ground, damaged pins is not an issue.
QUOTE(wilgo45 @ May 15 2012, 08:06 PM)

Check the ring of lights board - maybe swap it out
I used the eject buttom without the RoL board.
QUOTE(wilgo45 @ May 15 2012, 08:06 PM)

Look for missing SMD
None around the SMC. The only missing or visibly damaged one is C1E4, which is a coupling capacitor for one of the data lines for the HDD port. It shouldn't matter with regards to bootability.
QUOTE(wilgo45 @ May 15 2012, 08:06 PM)

Even try turning on the console outside of the cage - sometimes there are weird ground issues from the bottom side
I always use an antistatic bag when diagnosing motherboard issues.