There was I, browsing away, minding my own business on Friday evening, when all of sudden my Netopia Cayman lost sync.  I tried rebooting it a few times but no joy. On reboot, it would respond to a few pings and then stop. I rang Eircom Saturday morning and after going through all the questions, eventually, they said they would have a replacement router out to me by Tuesday at the latest.

I asked a friend of mine if he had a spare router, which he did, but he suggested that I first try replacing the PSU, as he had a router display similiar symptoms previously and it turned out to be the PSU.

Turns out, that the PSU is where the fault lies.  I plugged the router into the shack power supply and all is well again (As an aside, I now know that it uses 0.3Amps at 14.0Volts).