Where would I be able to get a replacement power brick for a Vigor 2820?
There was a lot of lightning this afternoon and when I got home from work the router was dark. The surge protector strip protecting it appears to have died but everything else connected to it appears to be okay.
I'm hoping that its just the power supply brick that's gone rather than the router itself so I'd like to test that before I look at replacing the router itself.

Any suggestions?

What is the voltage and current rating of the power brick? It should be printed on it.

Contact Draytek.co.uk

They sell replacement PSUs.

I have just had my PSU replaced. It went fizzle and then bang.

If Draytek can replace it under warranty OK, but then don't mention the lightning. If they won't, a generic multi-voltage switched-mode power supply will probably be a lot cheaper if it is a DC power supply. AC can be harder to get the voltage and current you want, but again Maplin do 3 .