PC display shows no signal after upgrading RAM

I just bought this PC for my wife from CyberPowerPC. When it got delivered I plugged it in, hooked it up to a spare tv, and set up the pc/installed some games. I ordered some more RAM to go with it, and after installing it no longer shows display on the monitor.

So far, I’ve checked all the cables, made sure the RAM is properly installed, made sure the HDMI cord is plugged into the GPU, and putting the RAM sticks in different slots. Nothing has worked.

I read online somewhere else that I should try taking out the CMOS battery and putting it back in, but I can’t find it. Google says it should be next to the BIOS chip, but I can’t find that either. Here are some pictures: https://imgur.com/a/vopsuCA