GTX 970 Not Booting / Fans Stuttering

[stockleymatt]

I have an old PC that needed an extra kick so I decided to pick up a used GTX 970. Before leaving with the card, I played some games and ran 3DMark to verify it worked; all went well. When I got back home, I uninstalled all my old video drivers and updated my BIOS. When I installed the 970, no signal was sent to the display and the fans on the card would start, tick a little, then stop; to me, indicated a false start. My suspicions tell me that this is due to my Power Supply being inadequate. I would greatly appreciate your input.

Current Build:

• 
  MB: Gigabyte 990FXA-UD3 Rev. 3 (BIOS Ver. FC / PCI-e 2.1)
  CPU: AMD 1100T Black Edition cooled by Noctua DH14
  GPU (Old): XFX Radeon 6870
  PSU: Corsair CX600
  RAM: Corsair Vengeance Pro (2x8Gb)

Looking to Add:

• 
  GPU: EVGA GTX 970 SC APX 2.0

Before purchasing the GTX 970, and other than testing the card to verify operation, I went to EVGA's site and seen that they suggested it use a 500W or higher PSU. This is the same information from XFX for my 6870. This is why I am still skeptical as to the reason. More than that, PassMark notes the 6870 uses 150W and the GTX 970 uses 145W; so, it should be a more efficient card.

UPDATE:
I got my PC to boot and it was completely by luck. I tried to turn on my pc, but had no display signal from the card. I then performed a hard shutdown by holding the power button until the pc had completely shut down. By accident, I hit the power button again and everything booted up perfectly fine, including display from my 970. I installed the drivers, played some games, and everything was working quite well. No performance issues at all. I even restarted my PC, entered the bios and fixed up my ram and my turned off the turbo setting for my CPU (everything was set to default after the update).
Here is where I think some of this issues are arising. Firstly, the next day (after my bios settings were fixed) I tried to power up my pc and, again, no signal to the display. Next, I tried the power cycle as described earlier, but now my PC would not POST. I reinstalled my old card, the 6870, entered the bios, and set everything back to default. Now, with the power cycle, my PC boots up with the GTX 970 again.

 

[hang-the-9]

Technically a CX600 should power the card with no issues, but they are also a bit on the low end of power supplies for a gaming system. Best thing to do is try the card in another system you know should run the card and see what happens. Make sure all power cords needed are in the card, sometimes people confuse CPU or some other power connectors for the PCIe power.