Looking for solutions on how to enable graphics card over the on board one and if i have to buya newone

[OTAKU_DESU]

My computer worked just fine for nine moths. But when I chnaged the PSU because of overheating when I played AC4 , the time I boot up the system, it displayed 'NO SIGNAL' on the screen, I switched the VGA to the onboard graphics card and it displayed normally but in lower resolution. I restarted y computer and I put it back to the GC's VGA slot it again shows the 'NO SIGNAL' sign.

I'm now using the on board GC

Specs:

PSU: Across ATX-600w (old)
PowerChoice 750w

CPU: Intel dual core 3.10GHz

OS: Win10

MB: BioStar 81MHV3 Ver. 7.x

GC: Palit NEAT6300HD41-1070F (Nvidia GeForce GT 630) 2GB DDR3 Graphics card

Help me please.

Did I fried the Graphics Card?
Do I need to buy a new one?
Can I still make it work?

 

[hang-the-9]

First, changing a power supply will not help at all with an overheating issue, you either misdiagnosed an issue you were having as overheating, of if your system was actually overheating, it still will be.

Second, I don't see any info out there about the PowerChoice brand, you probably went from one bad quality power supply to another.

To see if the video card is good or not, test it in another computer.

If the card works fine in another system, get a better power supply. For your system a 300 or 400 watt power supply is plenty. Antec, EVGA, XFX, Rosewill are some brands you want to look at. Don't buy odd brands based on price.