I just fired up an ebay modem that came from France. Had big problems with it, could not get it to talk to me no matter what I tried. The device was doing the right thing with the LEDs, they were flashing in a sensible and familiar pattern, and in that sense it seemed to responding as you would expect, so it clearly was far from dead. The seller claimed the device was new. In the end I had to do the 20 second bad-flash recovery thing to get control of it. It was as if someone had blown some very bad stuff into it or had set up a config so that I had no chance of guessing where the admin IP i/f was hiding in terms of IP address for the admin http server or its TCP port value.
Anyway, got it up and running in the end thanks to tip obtained here about the bad-flash reset ritual.