Question No post, fans don't spin

[mattr3 4]

i have a Hp prodesk 600 g2 mobo that is use with a new psu in a different case from the original hardware.
This started when I tried installing a new GPU (I have a different power supply that I use from the original). I had no problem installing it but I could not go into to post.
List of things I've tried
-unplugging everything except for important pwr cables (including removing gpu entirely)
- resetting and removing cmos
-switching power supplies
-switching power switches
-taking ram out to see if there are beeps (used put the original speaker that came with the product; don't know if it works for error beeps)
-used only dimm slot 1 from boot
-took the motherboard out of the case now making sure no cables are grounded
-screwdriver test with power switch
The green light is still solid on the motherboard. when trying to boot no fans spin nothing happens almost like I hadn't even pressed the switch. I noticed if I have the cpupwr and the pwrcwm in the psu and cpu fans spin but plugging in the pwr stops it.
Help would be appreciated because I've run out of ideas and I think I killed my mobo.
Thanks in advance.
diagram of mobo
https://www.hardware-corner.net/wp-content/uploads/compare/HP_ProDesk_600_G2_SFF_motherboard.jpg

 

[rgd1101]

and this new psu brand and model?
and the gpu model?

 

[mattr3 4]

and this new psu brand and model?
and the gpu model?

full specs
i5 6500
8gb 2133mhz crucial ram
hp prodesk 600 g2 mobo
rx 480
evga 500 br