Why isn't the 1XB completing calls?
35:12
How does a No. 1 Crossbar work? - Dial Equipment Appreciation, Part 2
23:18
How many different ways can we cause trouble in the 5XB?
27:08
At the Connections Museum: the insane telephone technology that led to today's computers
31:12
Full Mechanical: The Panel Telephone Switch
35:35
All calls are failing in the Panel office!
26:27
The 5XB Trouble Recorder
28:19
Malfunctioning Potted Relays: Emergency Repair in the No. 5 Crossbar
49:03