My Sense won't stop vibrating and the screen is black

[gecko378]

I'm trying to get my mom's fitbit working again since she's busy at work but I can't seem to fix it. It's a fitbit sense 1 and it's just vibrating nonstop. I've tried holding the "button" to restart it like the guides say but nothing is happening at all. No icons are showing up on the screen whatsoever. I've plugged the charger into a different outlet and the clock face can't be reset or changed because the app can't connect to the device. I'm pretty sure the device isn't dead because it won't stop vibrating, but I don't know how to tell if it's even charging when I plug it in anyways. All the solutions I tried to look up so far just say to hold the button down to restart it and have an icon show up on the screen but so far nothing like that has seemed to work. Any advice for this is welcome because i'm not very good with tech support

Moderator edit: edited title to clarify

[CrisVillaFitbit]

Hello @gecko378 , it’s nice to have a new face in the community.

Thank you for letting us know about this situation with your mom's Sense and for the steps you’ve taken to help solving this situation. 

I created a new case about this situation so our team can review your details and will contact you as soon as possible. I recommend you to check your inbox, so you can respond back whenever you receive the email.

[JayBee6]

This exact thing just started happening to mine this morning. And this is my warranty replacement after the first one was stuck on the flashing logo screen. 

[EvgART]

I was playing Tennis this evening and tracking was on, but suddenly screen went black. After 15 mins or so it turned itself back on and I saw battery on 45% and after more time it went black again. Sometimes pressing button triggers long vibration, other times it does nothing, holding power button does nothing. Connecting charger doesn't do anything as well.