Computer doesn't boot all the time

[Guest]

Ever since I acquired the components for my current PC, it rarely would boot the first time.
The routine was:
1. Press power button
2. Fans start spinning, HDD would power on, LEDs would start blinking ->no POST, no OK beep, no signal on the monitors -> hang forever
3. Reboot
4. Either back to point 2. or successful POST and OS load

Usually takes between 1 to 5 reboots for a successful load.

Motherboard - Gigabyte GA-B85-HD3
Power source - Corsair HX 750
Video card - Club 3D Radeon R9 280X royalQueen 3GB DDR5 384-bit
Dual screen setup through DVI and HDMI (the problem occurs with only 1 monitor plugged in also).

Recently, I removed the video card from the computer and by using the integrated GPU I get successful boots all the time.
Today I received the GPU back from warranty and their answer was "tested OK".

The power source is the one component I used in my previous computer and it was working just fine.

I'm hoping someone here can give me some suggestions which I could check myself before paying the 'premium' fee to the vendor to tell what component is the faulty one.

Thanks!

 

[spooky2th]

Have you set up the BIOS plus the memory speed & timings?