I recented moved back home with the mother who has a motorola SB5100 modem (no wifi). My old modem (which does have wifi) is an optus DPQ3925. Is there a way to connect it to her account? I tried just plugging it in and going but it said the internet was connected but nothing will load so I assuming it is linked to the wrong account? Any ideas?
So your mums modem works?
You might need to contact Optus and they might need to register your current modem or the like (you have put your mums optus password and login into your modem?).
However it could also be a setup issue where your modem is on a different IP range to your mums setup (192.168.0.1 - 192.168.0.255)?
Its also possible you could plug your modem into your mum's modem (ethernet cable). Set up its wifi and just disable its built in cable mode. First challange here is to access your modems settings menu when plugged in this way.
Note the main thing is to keep the internal IP addresses straight (so make sure they don't have the same one if both are plugged in. If only your modem is plugged in then it should have the same IP address and gateway etc. as your mums.