Power Reset HP Omen O15 Without Removing Back Case

My HP Omen 015 refused to start after shutting down. Some static electricity or limbo state? I had to power reset it. But there’s no such button on this. What can I do?

I tried all kinds of advice and key combinations from the internet.

Nothing worked.

But then I remembered, on the left side there’s an always-on charging USB port on this laptop.

I connected a power bank to it and let the computer charge the power bank, overnight.

By morning the computer was out of battery and switched off fully.

Then I plugged it in to AC power and started it up again as usual.

It opened fine. A power reset had been achieved.