S21 Ultra has Black Screen

Try this soft reboot method

1. Press and hold the Power and Volume Down buttons.
2. Continue holding the buttons until the Samsung logo appears.
3. Release the Power and Volume Down buttons.

Just tried that soft boot option again and I don't think it worked but it just beeped so maybe it is working but the display is gone.

Could be.... but if you can see it a little bit... it could be the back light is either out or the brightness got set way down. Can you take it somewhere very dark to try to adjust the brightness back up, maybe?

I can't see any lights whatsoever.  It sounds like it does a soft boot but nothing on the phone lights up.  I think I may just take it to the AT&T a mile or two away.  I have no idea if they can help me but maybe they will open the phone so I don't have to deal with that whole procedure.

Hello ScottyJ, we're here to help you with your black screen inquiry.

As the ACE @SoloTX mentioned, the soft reboot may help. If that doesn't help try to see if you can perform a factory reset that doesn't require the phone to turn on.

This will erase all data on your device and restore it to factory settings. To Factory data reset your device, swipe down from the Notification bar then select the  Settings icon > scroll to and select General management > select Reset > Factory data reset.

Note: A Factory data reset will revert the device back to factory settings. It will permanently erase all personal data, preferences, settings and content such as pictures, ringtones and apps that are saved to the device. It is recommended that you save (backup) important data before proceeding.

Let us know if this helps. Reach back out to us if you have any other questions.

Jeff, AT&T Community Specialist

Yeah if the screen is out entirely, you'll need to pursue warranty through Samsung, assuming it's less than a year old and there isn't any physical damage to the device. An AT&T store can try what you've tried and look into insurance options as well if physically damaged, but they won't "open up" the device in any way. Repair shops will but it'll void the warranty if any exists.

Jeff (ATT), I cannot see anything displayed on the phone, so how can I follow those steps?  You are suggesting I do these steps from the phone, right?

Solo, I have insurance on the phone so it better be covered.  What's going to get me is how much deductible they charge me.  If I get a new phone out of this, I guess that will be good, but I do not want to be without a phone.

If I open my phone, will that void my warranty? 

Yes, opening up the phone in any way will void the warranty, if not done by a certified technician during a valid warranty repair. It will also ruin your water resistance, as an extra FYI. Usually new/like new replacements are sent via mail in either case of insurance or warranty, but Samsung may have you take the device to an approved repair center in your area if one exists. They'll have to tell you where one is.

Also, to be clear, insurance is separate from warranty. Warranty is for malfunctions within the first year, like you're describing, so long as there's no physical/liquid damage beyond normal/expected wear and tear. Insurance picks up physical/liquid damage and malfunctions after the first year. You pay a deductible for insurance replacements whereas the warranty is free.

You will hat a refurbished phone not a new one through insurance.