Why won't my ADSL hardware sync?
The first stage of installing ADSL is getting the ADSL modem to "sync" to the exchange, until this happens you cant login.
There are several things to try:
Check all the leads are in the correct places.
Remove all the phones and other telephone equipment from the line and check again.
Remove any micro-filters.
Try the modem at the master socket, you can also unscrew this faceplate and use the internal phone socket which should bypass any alarm/extensions you have.
Check the ADSL mode the modem is using, try in the following order Auto,DMT,ANSI.
If possible try the modem on a known working ADSL line or borrow a known working modem.
At end of the day if you have proven the hardware to work elsewhere and ruled out your wiring then a reasonable chance the line isn't really enabled yet.
Please raise a ticket directly with 123vISP Support if you have any further enquiries.