Question Motherboard will not work with certain Video Cards

[Kungpow]

I have an MSI z77a-g41 mobo and for some reason, it is really picky with video cards.
I have a Gigabyte R9 280X and a ASUS GTX 780 that does not display a video output on a 500W PSU.
Then I tried an RX 480 8gb and an ASUS GT 710 on the 500W PSU and it works perfectly.
I swapped to a 650W PSU and it did not run the Gigabyte R9 280X so I swapped back to the 500W PSU.
I then tried again using ASUS GTX 780 with at 500W PSU and it did not display any video.

I attemped to turn off the integrated video graphics and it worked temporarlily with the ASUS GTX 780 and 500W PSU but it went back to no signal upon restarting.
I also tried using a 3rd gen I3 CPU and a I5 2500 and it did not make a difference.
I also swapped the ram in different slots and it did not work.

The strange thing is that when I took out to swap video cards from integrated graphics to dedicated, or vise versa the computer would turn on for 2-3 secs and shut off then turn on again. Now after playing around with the integrated bios settings it does not do the strange restart.

I am going to update to motherboard bios but this mobo is really finicky.

 

[rgd1101]

make and model of this 500w psu?
test with a better psu?

 

[Kungpow]

make and model of this 500w psu?
test with a better psu?

I actually managed to fix it. The r9 280x is finicky, for some reason it only works in certain PCI-E slots.
I will just leave it as is.

Thanks