PS4 won't connect to controller

I have recently bought a second hand PS4, when it arrived, it was working perfectly with the consoles connected. We did a factory reset to get rid of the last person’s info etc. on it. Now when we try to connect the controller via USB cable, it flashes orange and then flashes white once when I click the PS button.

We have:

• Tried hard reset of PS4
• Reset the controller using small button at the back
• Held down the Share and PS button to get flashing but then nothing
• Unplugged the PS4 and tried again
• Used different USB cables, including official PS4 Connect and Play ones
• Put the PS4 into Safe Mode but it asked to connect controller

When I connected to my PC to diagnose any problems, there were none, and when connected to play the console went blue so I am confused – what could be wrong?