Graphic card upgrade from geforce 530 to 740

[SMW47]

The connection with my primary monitor went black after moving monitor, my secondary monitor is fine

I check connections , change cables, bought new cables just in case they were the cause, even swap the monitors and try to see if it was the monitor.

monitors both work.

so i check the connection on the graphic card. I have a GEForce 530 card

I went and bought a new supply power of 400Watts to support a  GEForce GT 740 and the computer beeps onces and nothing, black screens

so i tried with just one monitor and still black , i cannot start it on safe mode it does not give me the options just the specifications and nothing else.

i even clear the RAM memory cards, clear the CMOS and unplugged and plugged the card back just in case.

nothing

still black screen

I return to my old card and it works fine but only one monitor, I need both monitors to be working.

any sugestions or you know if this model does not support an upgrade card ?

i have been researching already for couple of days .

thanks you

[wb2001 · Accepted solution]

Check with the manufacturer of the card. I suspect it's a UEFI VBIOS card, not Legacy.  Your system only supports Legacy. An explaination by @old_geekster can be found here.