Flashed the updated OS on the provided card
Flashed the OS onto a new card (using BalenaEtcher)
Checked every single internal connection to make sure they were securely seated
Took out the batteries
Took the case and keyboard off
Plugged it into the wall charger
Pushed the power button for the allotted time…
…and then, actually, there was a high-pitched whining sound coming from the main board for about 5 sec. Then nothing.
if you put in the batteries snd switch on, does the yellow charging light and the green light go on?
If not externally try to charge the batteries and try again…
If you have power and charging lights on, please check the screen with a flashlight placed close to the screen to see if the screen is on, but the backlight is not working.
if it is the backlight you can see the image on the screen with a strong flashlight, maybe the one on your phone is strong enough.
If you see a picture on your screen without backlight this is probably what happened
Update: Super-fast reply to my email. The thought is that it’s a completely unresponsive screen. A new screen is being sent, with one of the better endings to a customer service response that I’ve ever seen: