I have had my box for some time and have recently renewed my contract. In recent weeks though it has needed to be switched off at the switch and rebooted before working fine, but perhaps sluggishly.
Now though, turning off the box no longer works and it is stuck with the 3 lights flashing and freezes on the waking up screen although it progresses through the early startup/ loading pages. I have also tried the factory reset options and also rebooting the router.
Are you able to run any diagnostic tests remotely?
The model is DN372T