its cool, it happens, learn from mistake, but you were on the right track with the psu..
and its a dell psu, probably has a very low amp rating.. and the x1900xtx demands i think at least 30 amps
so you could look into a antec truepower tp2.. but i had mine running on a apevia 520 watt no problem as well
Intel 3770k @ 4.4 GHZ | Galaxy GTX 770 SLi | 16 GB G.Skill Sniper | ASrock z77 Extreme4
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Intel Core i3 3220 | Galaxy GTX 650 | 8 GB Corsair Vengeance | ASrock B75M | Samsung 840 120GB