The box has failed in the first part of the boot sequence, so replacement is the most likely outcome. You can either ring faults on 150 from any Virgin line (0345 454 1111 from others), use online chat (via the "Contact Us" link at the foot of the page), or wait a few days for the Forum Team to respond here.
Cable customer since 1993. Services: FH TV, Sky Sports & Movies (2xV+), Talk Unlim Telco, VIVID 100, Virgin PAYG Mobile
I'd like to take this opportunity to welcome you to the forums and say that I'm really sorry to hear that you've been having some issues with your V+ box.
I've taken a look at things for you, and can see that you've been in touch and have a technician booked. Testing on the connection does show that the V+ box is now broadcasting a channel, so it does appear to have come back, however the testing is showing some signal errors which will need the technician to call and investigate further.
Please let me know how it all goes with the technician.