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Iphone XS continually showing apple logo or black screen. Connected it to MacBook and downloaded new IOS for phone. Went back to showing logo or black screen and will not respond.
iPhone XS, iOS 14
Check this link...
If that doesn't help, check this link...
If your iPhone, iPad, or iPod touch won't turn on or is frozen - Apple Support
If that doesn't help, it may be time to make an appointment at the nearest Apple Store for an evaluation and explanation of your options.