Welcome to the Community Forums, thanks for your first post!
I'm sorry to hear you're having some trouble with your V6 box and that it won't start up. We'll most probably need to replace the box if it's failing to start up.
I've been able to locate your account and I have arranged an engineer visit for you - to view your appointment time slot, please sign into your My Virgin Media account or app and head over to your orders page. You can also reschedule the appointment from there if needed.
Do keep us posted with how the visit goes, and if you need anything else from here.