Pc wont boot after upgrade, and broken case cable. Potential shortcircuit?

[batmanthesuperMAN]

Old Specs:
CPU: FX-8320
MOBO: AsRock 970 pro3 r2.0
RAM: 2x4 GB gskill ares
PSU: Coolermaster v650
Case: Spec-01

New Specs
CPU: i5-6500
MOBO: Gigabyte Ga-h170-hd3
RAM: 2x4 Hyperx DDR4
PSU: Coolermaster v650
Case: Spec-01

So I installed new parts, and went to boot. All fans, LEDS, kb/mouse leds lit up and "working". But no video signal, I turned it off by unplugging it at the psu or flipping the switch because it was unresponsive to me pressing the power button (maybe it would of restarted automatically I wouldn't know). I tried turning it on again it would restart every 15 or so seconds infinitely. Whenever I unplug to stop the loop and try and see if I can fix it, everything starts/lights up for 1/2 a second.

I have:

-Checked all power connecters and reseated them
-Reseated ram in different configs
-Reseated Cpu/Cooler
-Checked for screws.
-Reseated video card
-Using onboard graphics with/without video card plugged in
-Changed and reseated all sata connecters
-Cleared CMOS via jumpers

But what I have found is that at some point, I cant remember when but my leds on my kb/m stopped lighting up (because of usb cable not the periphials being broken). I checked the usb cable and one of the wires on it are severed because it was streched too far. Could this create a shortcircuit and damage my mobo/components? Also how do I replace it...

 

[RARRAF]

the usb cable to whatever devices is not doing any harm to your PC the turning on and off sugests its overheating you have speakers attached to it ??

 

[batmanthesuperMAN]

No I don't have a speaker, might not need it now that the PC won't even turn on.. Just a clicking noise from the PSU the first time I press it after plugging it in.. Then nothing.

 

[RARRAF]

cheak the cables are all good return it if you can or get a new one tier 1-2 are good http://www.tomshardware.co.uk/forum/id-2547993/psu-tier-list.html