UPDATE pulled out the mobo, placed it on the anti static plastic, and powered it up....same symptoms/problem.
CLIFF-NOTES: 8 pin power is plugged in the mobo. when the psu is switched and and plugged in and i slowly insert the 20 pin connector to the mobo (the motherboard is a 24 pin) AND hold it at halfway, everything will power on. pretty lights turn on, PSU kicks on and boots up. the problem is that it wont do this when the 20 pin is plugged in all the way or even slightly off from that "sweet spot." what does this mean?
PS...the mobo was an open box from newegg so i was thinking that might be the ultimate cause of this ridiculous problem. everything else is brand new.
so here's the deal. i had everything assembled and ready to go...plugged in the psu, flipped it on, and it refuses to boot up. no lights, fans arent spinning, nothing.
so i took out the hsf (kept a fan plugged into my cpu_fan slot on my mobo), took out my ram, gpu, unplugged my hdd and dvd drive....tried it again...no dice.
the 8 pin power connector is plugged into the mobo and the psu is in good working condition (pulled it from my friend's rig). continuing on...
so i, for whatever reason, slowly inserted the 20pin into the 24 pin slot and at a certain "sweet spot" (somewhere in between being fully locked into place and not being plugged in at all), everything powers up (LED's, PSU, etc) and it begins to boot. what's the deal??
Motherboard: Gigabyte P55-USB3 ATX
Processor: i5 760
Memory: G. Skill 1333mhz ddr3 dual channel memory (2x2GB)
GPU: eVGA GTX 460
PSU: XION 1100W...i also tried my Antec 650W (which is known to work also....same thing happens)
and of course a sony dvd drive, seagate 1tb hdd, thermal take hsf...if you really need the specifics to solve this problem, i'll gladly take a closer look and post the specific specs for the dvd, hdd, hsf, case, name, rank, and serial number.
thanks again for your brain power and time, gentlemen.