cable munufacturing fault

"Bill Wright" wrote in message
...
Madam has a pair of Philips headphones, with which she listens to the
telly when I'm snoring. She complained that the right side was
intermittently dead, so I had a look. At first I thought it was the little
in-line volume control, but it wasn't as it turned out. Moving the (very
long) cable slightly caused the fault to come and go. I ran the cable
along the floor in a straight line and put books on it at intervals to
prevent movement being transmitted along it. I wiggled each section until
I found one where the fault occurred. Bit by bit I narrowed it down until
I became certain that the fault was inside a section of cable only about
100mm long. This bit of cable looked and felt completely innocuous.
Nevertheless I stripped the outer sheath off carefully. Inside were three
very thin multistranded wires, each insulated with plastic. After only
40mm I found a 25mm section of one wire with no insulation. The bare
length included a joint, made by twisting the two wires tightly together.
This joint looked as if it should conduct without difficulty, but in fact
moving it made the audio come and go. So is this what happens in wire
factories? The roll of red comes to end half way though a run so someone
starts a new one and just twists the end together? Blimey!

Bill


Nice fault finding :-)

Regards