Computer turns on but no BIOS (new build)

[mreitz.dmu]

Specs:
CPU: Intel - Core i7-7700K 4.2GHz Quad-Core Processor

CPU Cooler: Rosewill - RCX-Z775-LP 33.5 CFM Sleeve Bearing CPU Cooler

Motherboard: ASRock - Z270M Pro4 Micro ATX LGA1151 Motherboard

Memory: G.Skill - Aegis 16GB (2 x 8GB) DDR4-3000 Memory

Storage: Inland - 480GB 2.5" Solid State Drive

Video Card: MSI - GeForce GTX 1080 8GB DUKE OC Video Card

Power Supply: EVGA - B3 450W 80+ Bronze Certified Fully-Modular ATX Power Supply


All of the above parts are brand new, never been used before.

Initially when I put it together, it wouldn't turn on whatsoever. I switched around the RAM, eventually finding success with a single ram stick in the A2 slot (it turned on, sputtered off briefly for 1 second and then went on and stayed on). The CPU fan, GPU fans (x3), button LED, fan LED, and case fans (x2) were all running. The monitor continued to say nothing was connected (I have used this monitor many times before and am sure it works)

Next, I unplugged the case fans and the hard drive- same result. It turns on but no BIOS.

I tried swapping out the power supply for a CX500M 500W (used, know it works), and the thing turned on (no sputtering with this one) but again no BIOS. I added the second memory card into B2 and it turned on as well, so it seems that the RAM may have been fine after all. The weird thing is I tried swapping back to the other power supply and it turned on with both RAM sticks this time plus all the fans (reproducible).

No beeps with speaker.

Anyway I am not sure what to do next. This is the 4th computer I've built but haven't run into this issue before. Please and thank you with any suggestions.

 

[asoroka]

Have you tried using the onboard graphics, so no GPU and just one sticl of RAM.

 

[mreitz.dmu]

Have you tried using the onboard graphics, so no GPU and just one sticl of RAM.

I haven't tried that.

I should mention the build is in a custom hand-made wooden case and it was a pain in the butt to get the motherboard and GPU fitted in nicely (had to remove part of the GPU frame and put it back on after it was plugged into the motherboard).

I suppose I can try that tomorrow.

 

[asoroka]

one step at a time.

Does it work on the bench (no GPU and 1 stick of RAM).

then get that working in your custom case.

 

[mreitz.dmu]

one step at a time.

Does it work on the bench (no GPU and 1 stick of RAM).

then get that working in your custom case.

Did this and it worked. Re-seated the GPU and it also worked. My guess is it wasn't properly seated. Now to try and get it back in the case...

Thanks!