Black screen (no signal), no beeps, no power to mouse and keyboard

Hello,
This is going to be my first post on this forum and i am not sure if I am posting on the right place if so, feel free to delete it or move it where it belongs.

So... here is the problem:
A few days ago I connected my PC to my fathers TV. Everything was working fine until I decided to change the resolution. After I changed it I did not get blank screen instantly like you normally do if the resolution is not supported by the TV (which is not, but I found out that later). Then I restarted the computer and I got "no signal" on the TV, fans were spinning, hdd was spinning, my sound card glowing, and no power to my keyboard or mouse. I have no beeps too, but I can't say for sure because I noticed I don't have an iternal speaker.

Things I have done so far:
-Reset the CMOS
-test the ram and videocard on another computer, both working perfectly fine
-use different cables
-use different monitor that does not support that aspect ratio either and end up getting the same result
-remove the GPU and plug the HDMI cable on my mobo instead, same result
-remove the CPU power 4pin to see if something different happens. Yes it does fans spin for like 2 seconds and then the PC turns off
-plug and unplug HDD and SSD

I can test with my brothers CPU, but I will have to wait to get my thermal paste delivered to me

system specs:
custom build
OS: Windows 7 64 bit with bblean as default shell
MOBO: Asrock b85m pro4
PSU: corsair 600w 88%
CPU: i5-4670
GPU: R9 280X XFX
RAM: corsair vengeance pro 9-9-9-9-24 1600MHZ
SSD: (OS is on it) samsung 840 EVO
HDD: WD sata 3 blue 500gb
SD card: Asus xonar phoebus solo

Note: IIRC I had semi problem with this monitor before which I fixed by using my default monitor which I don't have access to ATM, however I think my mouse and keyboard did power up, but I am not sure at all.

some boards have internal speakers now. if you ever had beeps, you know that something failed.
and switching resolutions was not the cause
besides keyboard the hdd indicator on the case might give you an idea wether windows is booting and you do have a display problem.
i'ts a good idea to take the mobo out of the case, try to get mobo+ram+gpu to work. short-circuit power on pins on the mobo with eg a screwdriver to power on.
other than that, you can only swap parts until stuff works again. ram and gpu were smart starting points. i recommend PSU next. mobo is possible, cpu failure very unlikely. 1 in 10.000.