PC Tech Thread

Got all the parts today, put it all together without issue but now it won't turn on for more than a minute at a time. At first it was because I didn't connect the GPU properly, but now I can't work it out. Tried with 1 stick of ram, 2 sticks of ram, different GPU, different PSU, checked the wiring for the buttons and LED's. I'm stumped, so I've given it to the computer shop downstairs to have a look at.

Does it get past POST?
Did you flash your Mobo?
Can you get into BIOS?