graphics card - System won't boot: Gigabyte HD 7790 1GB OC GPU issue or Corsair VS550 PSU issue?

Installed a new GPU, and PC won't boot. Turn it on and:

• No monitor signal at all (tried HDMI and VGA via DVI, on 2 working monitors).


• CPU and GPU fans DO spin, but


• No system beeps, no sounds from drives (they might make a small noise in the first 1 second or so, but there's definitely no OS loading or anything like that)


• If hit "power off" button it turns off immediately (no holding down for 3 seconds like usual)

If I put my old HD 5670 GPU back in, everything works fine.

But (plot twist!) card is not totally dead. My friend put it in his PC, and it works fine (he even played a game for 15 minutes, no issues). He has a Corsair TX850 850W and a Gigabyte MB.

So my main theory is: the GPU isn't getting enough power from the PSU. But is it:

• 
  

  Bad PSU? Seems unlikely, since it works fine with the other GPU. Also, the PSU Is brand new and 550W (single 42A/504W 12V rail). Overkill for this GPU. Corsair is a decent brand, but maybe just mine is faulty?

  
  


• 
  

  Bad GPU? Could it be drawing more power than it should be, somehow, or something? Supposedly HD 7790 needs only 21A/75W on the 12v rail, though this one is factory overclocked a bit... but should that triple the power requirement?

  
  


• 
  

  Something else? Could there be a motherboard incompatibility somehow? Both MB and GPU are less than a year old and PCI Express 3.0 x16.

  
  

Things I've tried:

• Re-seating the video card


• Testing PC with old GPU (works fine, same PCIe slot).


• Checked AMD's stated amp/watt requirements of a 7790 and my PSU (see above). My PSU can output twice the amps (single rail) and 5x the Wattage a 7790 needs.

Here are the full specs:

Gigabyte HD 7790 1GB OC GPU
Corsair VS550 550W PSU
4GB RAM
AsRock H61M U3S3 motherboard
i3-2100
500GB SATA HDD (2007-ish)
blu-ray drive (new)
PCI 802.11g card

Edit: Motherboard BIOS Update seems to have fixed it. (If anyone has same problem and it doesn't work, comment here).

Answer

I've seen that problem happen before with a brand new graphics card with 2GB of RAM. The graphics card worked fine on one computer, and the other computer wouldn't start with the new graphics card installed in it. The fans would spin, but there was no monitor signal at all, neither for VGA nor HDMI.

The first thing I would check to troubleshoot your problem is your ASRock motherboard¹. Maybe your motherboard isn't delivering enough power to your graphics card. A graphics card with two large fans like yours would require more power than usual when the system is booting.

¹ Motherboard BIOS update fixed it.