I can't
to find the specifications of that router. Is it standalone i.e. it doesn't have an inbuilt ADSL modem. Are you connecting it to Virgin Media Cable, or something else.
That it is refurbished is perhaps a worry. Do you know that the fault that required it to be refurbished has been fully repaired?
Whatever you do start with the router set to factory standards. If you've been fiddling with it's configuration get back to basics so you have a clean sheet to play with.
If connecting to the Virgin Media modem, you must power off the modem before you make any connection or change the device connected to the modem i.e. computer or router.