How do I swap out a 1wire extension?

[Jim Spark]

Hi,

So I have a 1wire extension that seems to have failed. I have no temperature readings from 19 sensors though the device link and green light is still flashing. It is 10 years old!!

I have unplugged it from the power and reconnected-no joy!

I have a second 1W extension monitoring another 3 probes.

The main 1wire manages all the heating and hot water. The secondary I can live without until I can get a new extension (just ordered one ;) 

I have tried swapping the two extensions but I simply lose all readings so I think I need to delete both extensions and get the miniserver to lean it again. My worry is I will loose the sensors and have to find, rename and effectively start over. 

OR will the sensors all pop up with their names and locations?

Jim