Why my screen when turned on just keeps flashing

When I turn on my phone it starts to go through with startup cycle and then instead of going through and opening the phone it should screen just keeps flashing over and over and over and over and over just flashing the screen with the time and never gets past that this phone started doing this about 3 months after I had it I bought a brand new screen I've took it everywhere but people here in Colorado they don't know how to fix this type of phone some people tell me it sounds like a software issue but I've tried multiple times to try to get a hold of somebody from Okie tell what's 0 success how can I fix this problem and continue to use my $600 phone