To get the bios screen you don't need the drives or more than one stick of ram. Remove what parts that are needed to narrow down what it could be.
Why do you suspect the CPU? Was there something not shared in your post?
I think I have a CPU problem and don't know how to fix it. So about 2 weeks ago my friend helped me build my first computer. Everything worked really well and I was loving it. I haven't touched my ps4 since. Today I was playing The Division for about 30min 40min max, which isn't much considering sometimes I'll play for two hours without a problem. Anyways I was playing and my pc just shut down without warning the temps were normal, according to after burner 80 degrees C. Now when I press the power button on my computer everything turns on inside of the case but my monitor says no signal and keyboard and mouse don't light up. I'm kinda annoyed and nervous since we just built it not too long ago. Thanks for the help everyone!
MOBO: ASRock 970M Pro 3
CPU: AMD FX 8350
CPU Cooler: Cryorig H7
GPU: MSI GTX 970
PSU: EVGA 600B
RAM: HyperX white 8gb
Storage: Sandisk ssd and 1tb seagate hdd
1 led strip