I used to have a person that would ask me to come over and talk nice to their computer. It always worked... after rebooting.
I remember many times PCs would stop working on the network. You could reboot until the cows came home. You could power it off and wait a week. Still wouldn't work. Finally figured out you had to power it down, unplug it from the AC cord (or kill the power strip), let it sit for 5-10 minutes, ORRRR.... unplug it and then push the power button while it was unplugged. Apparently there's a CAP in the network cards they had that would hold it in the non-functioning state even if you powered it off. By unplugging it, then pushing the power button, it drained the CAP and lost the hold on that state.
People on phone support would get really mad sometimes if you asked them to unplug it and keep it unplugged while pushing the power button. They'd argue with you:
"It won't turn on if it's not plugged in!"
We know.
Convincing them that we're not trying to turn it on by pushing the ON button is kinda tricky.