Question PC seems to boot up, but my monitor is blank and my peripherals don't light up

[signum_]

Ok, so basically, wanted to boot up my PC a few days ago, and at first, it sounded like everything was fine. The fans started, the power LED lit up, everything sounded right. Not sure about my SSD, but I definetly heard my second hard drive (HDD) running. Everything did not look right. My monitor doesn't show anything, it's not getting a signal. My mouse, keyboard and headphones don't light up as they usually do. The only thing that lights up is the little light on the mute button of my Blue Yeti microphone.

At first, I tried reseating my RAM. After this didn't work, I tried removing everything except the monitor. Then I took out my GPU and tried using my onboard graphics. I thought maybe my PSU was overloaded, so I disconnected as many things as I could, still nothing. Did a hard reboot, also nothing. I switched the cmos battery with a new one. In the end, I came to the conclusion that my power supply is probably at it's end, so I bought a new one. About 20 minutes ago I switched it out, made sure everything was where it's supposed to go, and still, it's doing the same thing.

I'm really starting to get frustrated, as I don't really have the money for a new computer right now, and was hoping someone could tell me what the secret magical solution is that will fix it in seconds.

 

[Nemesia]

If you have 2 sticks of RAM remove a stick and only use one.

Have you tried power cycling? Shutdown PC. Turn off the PSU using the switch at it's back. Unplug the PSU. Press and hold the power button on the case for 15-20 seconds. Plug the PSU. Flip the switch back to on at the back of the PSU. Start the PC.

You tried everything. What is the PSU you bought and what is your full system specs so I can know what you're working with.

 

[signum_]

If you have 2 sticks of RAM remove a stick and only use one.

Have you tried power cycling? Shutdown PC. Turn off the PSU using the switch at it's back. Unplug the PSU. Press and hold the power button on the case for 15-20 seconds. Plug the PSU. Flip the switch back to on at the back of the PSU. Start the PC.

You tried everything. What is the PSU you bought and what is your full system specs so I can know what you're working with.

Yes, have tried both. I unfortunately don't know all my specs by heart, I only know that my processor is an i7 (no idea which one), my GPU (not that it matters that much) is an ASUS Geforce GTX 660 TI, the power supply which I had before was a BeQuiet! L8 300W, and the one I replaced it with is a Corsair VS650. I have 2x8gb sticks of ddr3 ram.