Pc won't post after case swap. Mobo power on

I aquire a hp SSF business pc for free from work. Came with I5-4570, 120 ssd, 500 hdd. Pop in a low profile1050 and been using it ever since.
Hp power supply is rated only at 240w. So I added a a 450w with a 24pin to 6pin adapter.
I been wanting to put a bigger graphics card to do some gaming with it so when I got a 1060 from a friend, I decided to swap case to fit the card.

Grab a new case, plug everything and just when I thought I was going to start playing, no post.
Just fan spinning, mobo light on.
I did the usual trouble shooting.
Removing and moving rams to different spots,
Resting the cmos by pressing cmos button, removing all drives like hdd ssd, and even removing the motherboard out from case by itself.

So new mobo?
Any idea?

 

You didn't mention if you experimented with the new power supply or GPU, so you have to narrow down the issue.
--Revert the computer to its working condition: Use the old case, put back the old power supply and remove the GPU, then verify it still boots.
--If that works, change a variable. I'd probably take the parts out of the case, try to boot, then hook up the new PSU to verify that boots.
--Then install the GPU and verify it boots.
--Then put everything in the new case.

Somewhere in that chain you should find the problem.

Charles