HELP! Major Problems with first build

Hi. I just finished building my first computer and im not very happy.

Heres the story: I put together all of the parts, and connected all of the power connectors and plugged it in without a monitor. THe front led turned on, the dvd drive opened when supposed to, internal LED's were on (mobo, fans, graphics card), and the fans were blowing. Sounds good right?

Then, when connected to the monitor, it says "NO VIDEO INPUT DETECTED". I run through a mental checklist in my mind and realize that i forgot to plug in the 12 volt connector, expecting it to be an easy fix. Much to my dismay, the 12 volt connector is at the end of one of my PSU cords, and in a narrow gap between the heatsink and case wall. I eventually (took 20 minutes) manage to plug one of 2x 4 pin 12v connectors into the socket. I try to power up the computer and their is no response at all. No LED's, no fans, nothing.

That was last night. I just tried removing my large aftermarket heatsink and trying the connection with the Intel Stock one. Connection was easy to make this time, but again, no luck at all. I then tried unplugging the 12 volt rail and attempted to recreate the scenario that originally resulted in the fans coming on, etcetra. NOTHING.

I am afraid i either short circuited the mobo or psu somehow, or damaged the mobo while attempting to make the connection.

Heres a list of my (relevant) components:
Intel Q9550
Asus P5Q-E motherboard with P45 NB
OCZ 600W PSU http://www.newegg.com/Product/Prod [...] 6817341010
HD 4850 (Asus)
Antec 300 case (PSU mounting at the bottom caused not long enough cables)
Sunbeam Core Contact Freezer Heatsink


Thank you so much for any suggestions, advice, or any feedback at all.

thank for you for responding

i am considering entirely taking apart and rebuilding

the secondary cpu power connector (12 volt) was the problem, and its hard to tell on my mobo Asus P5Q-E whether its a 4 pin or 8 pin connection (manual says 8, but it looks like 4 pins are covered by black plastic guard.

That's not a guard, it's a guide. It's there so that people who don't have 8-pin power connectors will know which side to plug their 4-pin connectors. You were supposed to remove it if you have an 8-pin CPU power connector.

Try assembling the system outside the case on a nonconductive surface. A phone book works nice. Don't set the motherboard on its bag, since that's a conductive bag.