Precision T3500 doesn't start

My Precision T3500 doesn't start. It does not display anything after 2 quick beeps. Here's the specs

CPU - Core i7-960

GPU - Quadro 4000
Power Source - https://www.ebay.com/itm/NEW-750W-750-WATT-Gaming-Quiet-Blue-LED-Fan-PSU-SATA-ATX-Power-Supply-PCIe/401016740157?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Ram - Kingston 2GB 1Rx8 DDR3-1333 PC3-10600E ECC Unbuffered 1.5V Memory KVR13E9/2

I purchased just motherboard for Precision T3500, and I use open case and other parts, I just bought it at amazon and ebays

Please help