I recently upgraded the GPU of my rig to an Asus GTX 770. My system had a 600 Watts PSU. That meets the minimum requirements of the GPU, and the system works fine with that PSU. But I didn't like the fact that it was running on minimum requirements, so I decided to upgrade the PSU as well. I bought a Corsair TX Series CMPSU-750TX 750W from newegg. I replaced the PSU with the new one and plugged everything in. When I applied power to it, the LEDs on the motherboard and on the video card lit up. But when I press the power button, nothing happens, the system doesn't power on. I then tried unplugging all case fans, HDDs, SSDs, optical drive, only supplying power to the motherboard and GPU, but still nothing.
I had to leave before finishing troubleshooting this, and will only be able to work on it later on, but I wanted to run this by you guys. Could the PSU be DOA, even if power is somehow flowing through it, since the LEDs on the motherboard and GPU light up? Would the paperclip test give me a definitive answer?
Thanks in advance.