Computer won't turn on when plugging video card

[jcnieto21]

Hey guys,

I have built a brand new computer and I'm having a problem when I connect the video card.
Thing is I plugged the processor, video card, sata drivers and etc and I turned the computer on and all the fans started working but didn't get any signal from the video card to my monitor and the power on off button didn't work when tried to turned off manually.
I had to turn off the power supply from the back.
Then I saw I forgot to plug in the 12V pin to my motherboard, yeah rookie mistake...
then I did, and buttons are responding manually and so on, but then when I plug the video card on the motherboard the computer doesn't turn on anymore, it sounds like it is trying to turn but in in a couple seconds stays turn off.
Could the power supply be the problem like perhaps is not giving enough energy or since I didn't plug the 12V and turn on the computer anyway with the video card on it, is there a chance the video card has been damage?

On the other hand, please tell me if the power supply mentioned is recommended for all the components I have mentioned.

My specs are

Motherboard m5a97 r2.0 am3+
Processor AMD FX 8320
Video Card ATI R9 270
RAM Kingston Hyper 8 GB 1866
CD DVD Write SATA
HD 1TB SATA 7200 rpm
PSU 600 watts cooler master thunder

All the help is appreciate thanks.

 

[1LiquidPC]

Your PSU should be adequate for the job. I believe it's a "middle of the road" unit for Cooler Master. Have you tried resetting the CMOS? I would try reseating all the cables coming from the PSU again as well. No other cheap GPU laying around to test? I'm not sure if damage was done by not plugging in the 12V CPU cable or not, but I'd say it's a possibility.