New computer, display doesn't detect signal

[Chamberdog]

So I decided it was time to upgrade my processor/motherboard, considering how I can't play a few of the games I own because my current setup wasn't anywhere good enough. It was my first time building a computer from scatch. I've installed a HDD, GPU, and PSU before, but I've never built a whole computer from scratch. I had to play with the case a little, but once I got everything to fit in properly, I didn't have any problems hooking it all up. I recycled both of my hard drives and my GPU. Everything else is new. Once I had finally finished building it, I plugged it into my tv and powered it on. All the lights and fans were working, but the tv tells me that there's no signal. I went back and checked everything, only to find that there's a 4pin connector on the motherboard which my 750w PSU doesn't have a cable for. I checked my old 500w PSU to see if it had the cable, and it did, so I plugged it into the 4pin connector (leaving everything else hooked up to the 750w), but still had the same problem. As far as I can tell, everything else is hooked up properly. :\

So then, not sure what to do, I asked a friend for help and he told me to come here, saying you guys are really good with computers. Any ideas what I should do? I can post pictures or something if need be.

Here's the motherboard and PSU. I also put in 2x2gigs of DDR3, this processor, and I'm recycling a Geforce 8800 and two hard drives from my old computer.

Thanks.

 

[mpilchfamily]

The PSU you have does in fact have the 4 pin connector. Well on the PSU it is an 8 pin but it should be able to separate into a pair of 4 pin. That connector is the one that supplies power to the CPU. Without it you won't get eh system running.

I don't know what you had before and you don't mention what GPU you have. But most often if games aren't running well its the GPU you want to upgrade.

As for your monitor... you said it's a TV. How are you connecting it?