60UF850T usb ports and tuner stopped working

The tv tuner and usb ports stopped working at the same time on my 60UF850T. All other functions are fine, the display is normal. The tv hasn't been moved recently or had any cables installed or removed. The usb ports normally have one chromecast plugged in for power all the time and has had an external usb powered hdd plugged into the usb3 port for the last 2-3 weeks. I'm suspecting a power supply fault. Has anyone had any similar issues and been able to pin point the fault?