Question HP laptop stuck during BIOS update and won’t power off

[kujen]

I’m trying to fix a laptop that won’t boot. I created a Windows installation USB to try to repair Windows if that’s the problem, but it would usually crash or blue screen before I could even boot into that.

So as a last ditch effort I thought I’d try to update the BIOS from a USB using HP’s BIOS recovery screen. It’s gotten stuck at 29%. I know it says not to power it off, but I can’t even do that. Holding the power button does nothing.

What do I do? How do I get the computer off?

The model is HP Pavillion 15-cs00053cl

 

[kujen]

I unplugged it, let the power drain, and tried again. This time it got stuck at 100%

Edit:

Unfortunately I think the BIOS is corrupt now. After it got stuck the second time, I let it run out of power again. This time it said “flashing boot block” when it came back on. Then that got stuck around 43%.

I let it run out of power a third time, and now it is a black screen with a flashing white light code on the caps lock button - 5 long and 3 short. I can’t get back to the BIOS recovery screen anymore.