Well this is quite annoying, now I am having the same problem with another phone: An AT&T 5923 cordless-corded 2 line one

First huge amounts of static started to overpower the line, Then the handset started saying SYSTEM BUSY whenever I tried to use it, then when I tried re-registering the 15 digit number on this 8 phone expandable system (with which I am using a total of one phone), I started to get error message T23 PD and the handset display returns to SEARCHING.

If something has died on this phone, would it necessarily be the cordless bit which cant connect or the circuits in the base? When I search ebay for handsets, I see lots of people asking extremely fancy prices for it and even fancier prices for spare handsets! (When they are ebay "auctions" as opposed to Buy It Now dreamers, these phones do seem to fetch relatively high prices)

I also seem to remember having this problem with a brand new V-Tech phone a few years ago. Is this not linking to base thing in fact a very common problem?