That PC does seem to be a bit thin on features so I'm not surprised that a new PS would be needed. You didn't mention what PS you got for it but the specs do call for 30 A on a 12v rail plus some connector options. By any chance did you not connect the additional power cables to the graphics card? I have seen that to happen. The last thing I want to do is be insulting but I do need to ask. Good luck.
So, I recently bought a EVGA GTX 760 SC graphics card. Along with this I needed to upgrade my PSU to be able to support the new graphics card. When installing into my computer I only received a black screen and a beep from my computer. After hours of troubleshooting and googling, I've come to the conclusion that the problem was my BIOS being outdated. I searched and searched for an update for my BIOS but I could not find anything on the HP website. I even contacted EVGA and HP on this and they were no help. Do i need to purchase a new motherboard? If so, how do i go about finding a compatible one?
I have a pre-built system from HP.
Model: h8-1256s
Processor: i5-2400 CPU @ 3.10GHz
Motherboard: Foxconn 2ADA...
Form Factor: micro-atx
Processor Socket: LGA 1155
Feel free to ask for any more information on my PC if needed.

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