I agree, that does appear to be more of a hardware issue. Probably not a software-related one. Could be a more involved one where the display component has failed, or the GPU (integral to the main SoC), with either being an involved repair (the latter resulting in a new logic board so you're definitely going to lose any stored data.) Or it could be a more simple repair like the cord between the logic board and screen just needs to be reconnected -- i.e. one of the connectors needs to be re-seated. But yeah, send your phone a trusted phone repair service to have a trained technician do an assessment to see what's wrong.
Something else to keep in mind how much time and money do you want to put into repairing this phone?
It's a very capable model with good hardware specs but it's also a four yr. old model, so weigh your options as to spending money to fix it or put into buying a new phone instead.
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