Save settings if you can, not the default ones, but the real ones.
Maybe try with battery in addition to USB. Maybe try with ports disconnected. Maybe look for crushed pins inside mainport and flexiport.
It's possible that you enabled some options that caused this, for instance, CC3D is low on memory. Enabling many features could cause this.
Finally do Rescue (or just boot to default settings after normal boot failure) then Erase Settings and start over. Save settings as you go, before enabling a lot of stuff (e.g. telemetry and GPS for OSD).