If the green screen is the "DVR has detected an error" message, your hard drive has failed. Combined with a rebooting box, it's clearly faulty.
You can either call in to report this - 150 from a VM phone or 0345 4541111 otherwise - or wait here for forum staff to pick up, which may take a couple of days.
V6 box replacements are currently done by engineer visit.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks