I plugged in power supply main 24 plug cord into the motherboard, and the fan still does not come on and power the actual system. I had a shot power supply and I replaced that just today, I have no clue what is wrong with the system, I bought the same system but I made the guy a the store test it and it worked so I really have no clue what is wrong.
Here are my specs:
EVGA 01G-P4-2650-KR GeForce GTX 650 1GB 128-bit GDDR5 PCI Express 3.0 x16 HDCP Ready Video Card
ASUS P8Z77-V LK LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard with UEFI BIOS
Seagate Barracuda ST1000DM003 1TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive
G.SKILL Sniper Gaming Series 16GB (2 x 8GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model F3-1866C10D-16GSR
Not sure if that really matters but all the help is appreciated. I also tried just plugging in the motherboard and trying a different outlet so I think it must be that the motherboard does not work with the power supply or that the motherboard is broken.
The make and model of PSU would be helpful here, you say you plugged in the 24 pin power connector to the motherboard but do not mention the 8 pin EPS/ATX power, just to confirm that is also plugged in (with connector(s) that say CPU or EPS or ATX if anything is printed on them - do not use one that says PCIe or GPU)