Sigh. So we moved my son's desk & computer & now the monitor says there's no signal. Tested it with alternative monitor & HDMI cord. No difference. And the local computer repair place isn't open on weekends. Not frustrating at all.
@aysrick If it has a GPU and a Ryzen CPU, make sure you're connecting to the GPU's video port and not the motherboard's. The motherboard video port won't have any video output with those CPUs. Long shot but something I've been bitten by. 🙂