Another 870A-G54 not posting

Question

Well, here I am, yet another person with his newly acquired 870A-G54 MB not posting.  This is actually my second MB of this series.  The first one I RMA'd after it shorted in my case due to a rogue standoff hidden beneath the board; a stupid mistake on my part, but one which I thought I had corrected with this board. I removed all of my standoffs and then put one back for each hole in the MB. 
Now the current problem. I put everything together and turned on the board for the first time.  The fans spun up, the HDD light came on, and the 4 CPU power phase LEDs turned on. However, neither my mouse nor my keyboard received power, and my monitor remained in standby mode. 
All of the parts listed in my signature are newly purchased.  They are the hardware that I am using with this MB.  According to the MSI compatibility test results, the ADATA sticks, the 8500GT, and the Phenom II are all compatible. This specific Antec Earthwatts was not tested, but a higher wattage one was, and that was compatible as well. 
I know my first step is to perform a bench test with only 1 stick of RAM, the VGA, and my keyboard.  That test failed, so now I have some questions that you guys can hopefully answer for me. 
First: What do the power phase LEDs actually mean? I am trying to figure out if it is good or bad that all four come on and stay on, but the manual doesn't give any description beyond the fact that each LED represents a power phase mode, 1-4. I haven't found anything online that explains this to me. What are power phase modes? What does it mean if all four lights are on?
Second: Could any of my other hardware have been damaged by the first MB shorting out? I know that the VGA and PSU work fine because when I RMA'd the first time, I put my old rig together, but used these new parts in place of my old VGA and PSU.  I am wondering specifically if the RAM or CPU could have been scrambled. Just to note, there was no physical sign/damage when the first MB shorted; no smoke, spark, or smell, and there are no signs of physical damage (bent pins, scratches, or cracks) on either the CPU or RAM.
Third: Could this be related to my power supply? Despite the hardware itself being new, the model is old, but it has all of the proper power connectors for this board.  Here is a list of the voltage rails and the amps
+3.3 V, 25A
+5 V, 25A
+12V1, 22A
+12V2, 22A
+12V3, 25A
-12V, .5A
Does this power supply not provide enough power to the CPU?
Fourth: Compatibility tests aside, is it possible that the MB doesn't like the Nvidia card? Like I said above, I know that the VGA card works, but MSI seems to favor ATI cards.  I have a really old ATI Radeon card that I test with the board, if you think that would reveal anything. 
Finally: What besides standoffs making contact with the board could cause a MB to short inside a case?

Answer 1

    
No Post - Shorting issues
     Motherboard Grounding to case causing No Post
Test the motherboard outside of the case to verify that the motherboard is not shorting to the case and causing a problem
     •    With only the CPU and heat sink, memory, and video card (or onboard video) connected to the motherboard, place the motherboard on a non-conductive surface and retest the motherboard
     •    Check the case mounting standoffs to verify that they are lining up correctly with the mounting holes on the motherboard.
Also try with barabone setup [when testing with mainboard out of PC case], and 1 memory stick only in 1st dimm close to cpu socket.
Quote
PSU: Antec EarthWatts EA650 650W
The PSU too possible to have malfunction, Antec fails a lot.