if you took the working adaptor card from the known working tivo units and still could not get this tivo unit from ebay working, I would presume that this unit is not configured correctly or not working. I don't think it's the 655 router as you said the other 2 are working in the other room. Need to make sure your ebay tivo is set up right. Are these adaptors wired or wireless? Try using wired connection to the tivo if it has a LAN port first to test. If you get connection there then you'll know maybe this unit needs some configuration for wireless.