My A 15 Samsung phone of barely a week suddenly went black over night ..

[Madamdewhocares]

This is alarming  and sad … I got the phone as a gift from Germany ,I am here in Nigeria .. I didn’t drop the phone ,no crack but still it went black unprovoked .. and I was told warrant doesn’t apply to international!samsung needs to do better 

[Robin999]

Yes, that is correct. Your German handset is supplied with a European warranty, which does not cover you if the device is exported outside of the EU. It's clearly documented in the warranty terms.
With regards to your 'black' screen issue, try hard resetting the device by holding down the Power button and Volume Up button simultaneously for 10 seconds. When the Samsung logo appears, release the buttons. Hopefully, the device will boot up normally, and the screen should be working. If not, then plug the device into a working PC or laptop and repeat the steps above, but this time, release the buttons when the phones recovery menu appears. Use the volume buttons to navigate to Wipe data/factory reset. Use the power button to select. Please note that this will erase all your data permanently, so hopefully, you have a backup.

[BandOfBrothers]

@Madamdewhocares try > https://www.hardreset.info/devices/samsung/samsung-galaxy-a15/ 

Yes unfortunately a phone imported from another country may not be supported under the Samsung Manufacturer's Warranty due to the T&C's. 

It is best practice to purchase a phone from your own region. 

@deborahjane contact your network provider to ensure voicemail is activated for your account. Further information should be in theirbiwn support pages online 

If i can be of any further help please don't hesitate to ask  😎