Desktop wont start - fans start but Powerswitch led isnt on. fans just spin no startup. no sound

[Dompan]

PC is only a couple motnhs old and worked fine until I tried to put in an external GPU (GTX 1060) to upgrade graphics. PC started up w new GPU but there was no image on screen. Not through the regular built in GPU nor through the new GPU.  when I removed the GPU the PC still won't start up completelly. Fans for PSU, Chassi and CPU go on immediately when I plug in the power cord but There is no sound (beep upon start), no led lights on motherbord, no led light on the front Power button liked it used to. No image on screen like before. Also the HDD doenst seem to spin up like before. There is a built in SSD m.2 so thats what I have bin using so far. the HDD is empty but would spin up and make that typical HDD sound. It's now conpletelly silent. 

So when I put in powercord The fans just spin up immediatelly and nothing more happens w the PC. Beofre I would put in the powercord. Then I would normally have to push the Power button on front and then PC would start (the power button would be lit aftertthat). Now when I put the powercord I dont even have time to push the Powerbutton on front. The fans just spin up immediatelly and then nothing more happens. Powerbutton doenst do anything and wont lit up like before. 

Seems like a power / motherboard problem? any suggestions? I have warranty left but wonder if I can check/do anything on my own? 

thnxz in advance. /D

[Lil_Boy_Blue]

Hi
First:- Turn off the computer, press and hold the PWR button for 4 seconds.

Then - Leave only keyboard and mouse connected, disconnect all externally connected
devices such as Docking Station, USB storage devices, displays, and printers.
Unplug the AC adapter from the computer.

Next - Press and Hold the Power button for 15 seconds to Hard Reset.
Rinse and Repeat

Power on your PC, press Esc (repeatedly), then F2 at the prompt.
Choose System Tests (Fast Test does a 4 minute hardware check).
AND/OR
HOW DO I USE DIAGNOSTICS?

HP PC Hardware Diagnostics Windows is a Windows-based utility that allows you to run diagnostic tests to determine if the computer hardware is functioning properly. The tool runs within the Windows operating system in order to diagnose hardware failures. HP PC Hardware Diagnostics Windows comes pre-installed on new HP computers, but if not on yours, download here:

http://ftp.hp.com/pub/softpaq/sp93001-93500/sp93457.exe

AND/OR - Windows Logo key + Ctrl + Shift + B
(This key sequence actually restarts you graphics driver (W10 only).)

I suspect your warranty may not be valid in this case.