Power cycle when Rx 570 is inserted

[AllaboutBudget]

System specs:
Corsair vs450 (gray unit/label) 1 year old
samsung b75s1 mobo
xeon e3-1270
rx 570
2x4 kingston ddr3 ram

Okay so one night my pc's display turned off and even if the display is turned off, the system is still running so what I did was restart the system, but after restarting, it no longer posts

I resetted the cmos and got it to boot and it worked. ran all the tests I need and it did not show any problems. I did ram test,gpu,cpu stress tests, no error or what so ever. But right after I turned off the pc, it wont boot again. and up until today, it still does not work.

Things I have done:
tried different PSU, same result. power cycles when rx 570 is inserted
I bought a new gpu (r5 230). still no display. dont really know if the one i bought is DOA
right now I bought a celeron g530 and it boot right up using the iGPU

Now, when I plug the RX 570, it will cause a power cycle.
When plugging the r5 230 in, pc no display.

dont know if my pcie slot is defective or the gpus are shot?

please shed some light on possible causes.