new s20 phone, installed update and now it asks for a password (at least 4 numbers and a letter).
It won't even let be shutdown the device as it asks for this password, but it's something that was never set
Just purchased S20, and you never set a PIN, Pattern or Password?
Is it the Samsung Password screen or Google's?
If you have another device, can you post a screen shot of what you see?
You could always try your Google or Samsung account passwords.
But a Security Patch OTA shouldn't change, add or remove any previously set Security.
You can try entering 4 zeros, ie:
That is supposed to be Samsung's Default Unlock code.
If that doesn't work, you will probably need to visit a Samsung Service Centre to get it checked out by a tech.
I've never seen this happen before, although I'm sure that it must have.
It's remotely possible that the update had an issue installing. I'm not saying that the update was faulty, just that for some reason it didn't updated properly.
Link to locate a Samsung Service Centre:
Hi, where did you purchase the device?
You can try the unlock passcode provided by RedDogRabbit and check if the device is turning on.
If that doesn't work, you need to get the device examined by the service technician.
To know the nearest Samsung authorized service center please visit the link given above.