AV to HDMI 1080p Scaler Video Converter Outputting Sound But Not Video

I'm trying to connect my N64 to my HP 22cwa HD monitor. I'm using an Enko Products AV to HDMI 1080p Scaler Video Converter box (as the title states). I have everything plugged in, but when turn everything on, the audio comes through but not the video. The N64 works fine on my TV at home (I'm at college which is why I'm using my monitor), so it's not the N64. The monitor is supposed to automatically switch between video inputs, but when it scans for the HDMI input, it doesn't pick anything up. Based on all this, I can only assume I either am completely oblivious to something I need to do, or the HDMI cord itself is messed up (it's brand-new). Is there anything else I should check? What would be the next logical course of action in my troubleshooting?

Here's a video of someone successfully doing what I'm trying to do (albeit with a different converter box):