The PC passes POST and then just gives a black-screen (if I disable the vendor splash screen, if I enable it the splash screen will remain) and then freezes (won't even accept CTRL+ALT+DEL).
(My Display doesn't go into standby tho, so it seems the PC basically outputs a black image).
If I enter BIOS (which I am perfectly able to) and try to start the "EZ Flash Utility" to update the BIOS, the same thing, black-screen and it freezes.
If I enter BIOS and manually select a device to boot (which are correctly identified), the same thing, black-screen and it freezes.
I connected a SPEAKER and on boot it gives off one short *beep*, which seems to indicate everything should be fine, if I remove my RAM and reboot, it gives off 3 longer *beep*s, as expected, indicating this process works fine.
All components are correctly detected in the BIOS, CPU/RAM have the right vendor name and speeds.
RAM: G.Skill DIMM Kit 4GB, DDR3-1600, CL9-9-9-24 (F3-12800CL9D-4GBNQ)
(I'm unsure if the RAM is officially supported, tho it seems to be standard RAM)
What I have tried/Ruled out:
First of all, I have stripped the PC down to it's bare components, PSU/MOBO/CPU/RAM to test what I can eliminate and disconnected anything I wouldn't need (front USB connector from the casing etc.)
I reseated everything, , PSU connections, RAM, CPU
I tried running the PC both off one RAM stick (tried both slots with one RAM) and off both simultaneously [UPDATE1]
I have tried two different 400W PSUs, one of which works perfectly fine in another PC. - I made sure I used the right 4P CPU connector.
Instead of the built-in GPU, I installed a dedicated GPU and manually set it as default display output device in the BIOS, also gives a black screen.
I switched the RAM with the RAM of another PC, which is also DDR3, has bit different timings but is pretty standard RAM I expected to work. Unchanged behaviour.
I reset the CMOS multiple times, first through the jumper, then I took the CMOS battery out and put it back again. Unchanged behaviour.
I disabled every non-essential on-board component of the mainboard in the BIOS and plugged in a PS/2 keyboard instead of a USB keyboard, tried to start the "EZ Flash Utility", unchanged behaviour.
I am at a point where I think I have enough indications to return some of my components. I'm trying to narrow down potential problems. The fact that I pass POST and the fact that I can enter the BIOS and change settings around perfectly fine seems to indicate something works fine.
Does this sound like a damaged CPU?
Does this sound like incompatible RAM?
Does this sound like a faulty MOBO, maybe a badly flashed BIOS (my guess)
A question that's implicitly in here:
If I can make it into the BIOS, the POST passes and my components are deteced correctly, what conclusion can I draw?