New video card install.. black screen?

I just installed my new video card without installing the new drivers OR disabling the onboard memory. Knowing that I screwed up my computer boots fine but I do not get a connection to my monitor. I tried removing the video card and using the onboard with no result. Need help... I am currently using my iPad to find solutions...

I would first go into your motherboards BIOS and check and see if any video options are selected. Like, use only (onboard video), or use a (video card) only, or see if things are set to just (automatic detect). I'm having a funny little feeling that somewhere during this process, your systems BIOS has got haywire. If things are set in your BIOS as they should be I would recommend re-setting the BIOS, mainly done by a special CMOS jumper located on the motherboard. If you not know what I am talking about, please supply your motherboards make & model and we will see if we can guide you through the process.

Ok, to add more info. Currently I cannot get USB drives to work on the computer. My speakers are getting power but the keyboard nor mouse USB work. I cannot get into the computer to change any settings.

Computer: reviews.cnet.com/desktops/asus-essentio-cg5275-ar003/4507-3118_7-33964723
Motherboard: p5ql-vm epu

I reseated the memory. No change.
I disconnected all power and reconnected. No change.
All fans run, hd seems to be running, and I can access the disk drive.
Attempted to remove watch battery on mother board for an hour and then returning it. No change.

Problem fixed...

How? And what was it? Just curious!