Unsure if battery is pull-able on the s8 but if so, might help next time.

 

Press and hold the power button for 10-20 seconds. I've yet to meet a freeze with any phone that's so bad that that doesn't work.

 

I did. A known defect on S8. Problem with power button. Verizon sent me a refurbished phone for my brand new one. Would not power up at all. Very annoying to get a used phone already. Samsung would do nothing unless I shipped it back and it would take a week. Disgusting

 

Quality at it's finest...

 

Sorry off topic but I'd always thought that too. How wrong was I. Tried to flash a kernel earlier and it went horribly wrong. Honestly the closest I've ever been to a full bricked Samsung. I can't even call what I got a boot loop as there was nothing looping. It was just a solid Samsung Galaxy S8 logo. Holding power didn't turn the phone off. Couldn't boot it into recovery. Luckily I could still get into download mode. Another problem there though, can I download stock firmware on my PC before my battery runs out? It wasn't looking like it so I took a shot and flashed the TWRP I'd already got on there. Surprisingly it actually worked and put me into recovery. Thank you nandroid. So long story short yes you can have a freeze so bad that holding the power button doesn't work

 

Volume down and the Bixby button works too.