Pc not rebooting correctly

[Rooster 75428]

Hi,
I've got an unusual problem with my custom built (self built) pc.
Everytime that I attempt to make it boot the fans spin up but I don't get a display output.
It's not overheating since I haven't seen temps above 70C even in intense stress tests and usually about 30C (Room temp)

(*1)
The only way that I have found to make it work is to remove the CMOS battery and power on at the PSU, then the case power button. If I "shut down" from windows or perform any sort of soft power off, then it doesn't boot again but the fans start up.

So far, I have found that I can store my BIOS settings on a USB drive which acts like my CMOS/BIOS storage. I also can't restart the pc since that acts the same as a soft power off.

It's most likely that it is a software issue since I can boot to windows if I use the above step (*1)

If I hold the power off button on my case then I can power down the system, but attempting to reboot/reload anything leads to the fans spinning but no display.

I have no idea how to even go about debugging something like this. Anyone have any suggestions?

Hardware:

CPU
Intel i5-6400 LGA1151

GPU
ATI Radeon Cypress HD 5870

RAM
1X 8GB DDR4 3200MHz

PSU
Corsair CX750M -750W

MOBO
Asus Prime Z270-P LGA1151

SSD
Viathan 256GM M.2 PCIe3.0

Note:
I know the specs are bad, it's a PC to learn more about and be able to take parts to the limit on (CPU overclocking), also I only recently found out I can't really overclock the CPU so will need a new one.

[lafrente]

Can you try to boot by holding the power button down for a few seconds?

 

BTW I don't think it's a software issue. No software is loaded until after BIOS.

[Rooster 75428]

Hi,

I can get to bios to boot on the first power up, but on a second power up then I can't get any display, get to bios(visibly) or boot(visibly). Holding the power button just shuts down the pc after 6~seconds.

Even my usb stick doesn't light up on the second power up so I doubt it's getting past turning on the fans