Sorry, My bad: Ping response from the static IP address is "Request timed out". (forget Dest unreachable, that was my brain-fart). I have two unrelated devices within the same subnet and the "other" device is immediately reachable: "Reply from x.x.x.x. : bytes 32 time=3ms TTL 63".
I've re-verified that DHCP is not enabled, that the IP address, subnet and gateway are correct via the Flex 20 interface. I've also ruled out any firewall rules that might prevent communication either up or down.
I had also (in a previous chat with Stuart) ran a completely new ethernet cable from router to device and set this on DHCP - just to rule out any network misconfig. Still invisible (no IP connection seen at router).
My guess (in the absence of any technical testing capability) is that I have a fried A083-01. Frustrating, but I guess I'll be looking for a new one!
Thanks very much for your continued support and help
Derek