NEED HELP!!! PLEASE!!!!

I recently bought a new motherboard, gpu, cpu, and ram. A DFI Infinity 975X/G, MSI RX1900XTX 512MB, OCZ Platinum DDR2 2x1GB PC 6400, and Intel C2D E6600 w/ 650w Antec PSU. First motherboard i turned it on all the fans turned on but no bios screen or the start up beep. I switched it out w/ p4 (brand new cpu), dif ram, and dif video card same response. I cleared cmos and same response. I returned that motherboard and received a new one. I did the same thing and same response. Sometimes after starting it a couple of times it turns on and after 3 seconds it shuts of then turns on again in a few seconds? But the problem? This is the first time im using a Intel and DFI.

Could you elaborate more on the issue?

(For instance, checked the polarity of the power led connector on the MB? Checked the case's power button electrical integrity? Correct placement of all components? ...)


Cheers!

I think all DFI motherboard (at least mine does) have a button on the motherboard itself to power it on. You can use this without connecting anything from the case, so I'd try that. There's usually two of them (the upper one is reset, lower is power), located somewhere near the power (not standby) LED.