On Sat, 12 Feb 2011 03:04:15 -0800 (PST), Tabby wrote:

the problem normally only shows up after years of service in
applications where the cable heats up (and contracts). As it expands
in the connector it squashes (deforms), so when it contracts its no
longer gas tight. Aluminium loves to oxidise, and then you have a
somewhat insulating oxide layer in the connection.

And it becomes brittle. The ali wire in the "jelly bean" can fracture
at the IDC causing an open circuit but the insulation holds the wire
in the bean so it looks OK. The fracture can happen with very little
movement and stops POTS working, ADSL being RF can "leap the gap" but
at much reduced speed.

--
Cheers
Dave.