Video Game Console Repair Questions? Ask a Technician ASAP
Try entering PS4 safe mode.
turn off your PS4, when its off hold the power button untill you hear 2 beeps.
Then connect your dualshock4 and pres the PS button.
You should see the safe mode of the console, try changing the resolution to the lowest
If safe mode is not displayed then try another HDMI cable, if problem persist then the PS4 is damaged again.
Let me know if it works.