My recommendation,
Turn off the box and unplug it overnight. In the morning, plug the box back in and see if it completes the reboot. If it does and the picture comes back, you're all set. If the box is stuck on a reboot contact TWC to do some signal tests. The box may also need to be swapped. You can call TWC or contact them with this information:
Say you have done a cold reboot before contacting TWC. If you don't feel like calling TWC, send a PM indicating these box issues to
Satch