Upgrading Gateway DX4870-UB2C with geforce gtx 660 video card keep getting no signal on monitor

BeckyJo

Honorable
Dec 8, 2013
2
0
10,510
I just purchased a Gateway DX4870-UB2C desktop and changed out the power supply to a Thermaltake TR2 600W to handle the Geforce GTX 660 video card. When I put the video card in and turn on the computer all I get on the monitor is no signal.
I disabled the motherboards graphics through the BIOS, but still get no signal when I turn on the computer.
The geforce card's fan runs and appears to be working as it should other then the signal not going to the monitor.
I have tried with a HDMI cable also and still no signal.
Thanks for any help ya'll can send my way.
 

BeckyJo

Honorable
Dec 8, 2013
2
0
10,510
As soon as I posted this I received an answer. In the BIOS I disabled 'secure boot' and then I was able to switch LAUNCH CSM from Never to Always. Worked like a charm.