Strange Problem with Epee Wires

[Stormbringer]

During a bout, one of my club's electric epees simply stopped working. The point was dismantled and cleaned, but that did not fix the problem. The visible portion of the wires were checked for signs of damage; there were none. The hilt was removed and the wires again checked for damage; still nothing. the blade was bathed in acetone, and the wire carefully removed (with both wires still attached to the pins).

There appears to be no corrosion on the pins and no (apparent) damage to either wire. Even when moved from the blade (eliminating the possibility of grounding on the guard or the blade itself) and tested by holding one end of each wire to the appropriate ports on the test box (the two closer ports; the "A" and "B" lines?) shorting the pins against bare metal (a wrench), there is no response from the test box.

(The rewired weapon, using all of the same parts except the wire, works finely.)

What could cause a weapon to spontaneously fail like this? Is there some way to preemptively prevent this from happening? Is there a way to restore functionality without rewiring the weapon?

[Pescados666]

You could check the continuity of the wires with a multimeter, although I am not sure how it would work as the wires are already ran.

[Stormbringer]

Originally Posted by Pescados666

You could check the continuity of the wires with a multimeter, although I am not sure how it would work as the wires are already ran.

What, precisely, do you mean by "already ran"?

The multimeter is a good idea. *Stormbringer wonders why he didn't think of that*

I'll try it later, and post the results...

[SJCFU#2]

Presumably you started off by looking for the obvious things, such as a wire broken off at the socket or a bad body cord.

Once you've done than I would suggest plugging your tester into the socket, removing the tip, gently sticking are screwdriver down into the barrel and try shorting the contacts together (ideally without touching the side of the barrel). If your tester indicates an A-B short then it's likely that both wires are still intact and you might want to take a closer look at the tip. If the contact spring is out of alignment or the contacts aren't level then the contact spring may not be able to touch both of them. If you suspect the contact spring then you may simply want to replace it (they're cheap enough that it's difficult to justify putting too much time into one). If the contacts aren't level then you can try pushing them down with a point setter. A good cleaning can also sometimes do wonders.

If you don't see any signs of life when shorting the contacts together then try testing the individual wires by plugging one of your multimeter probes into either the A or B socket and poking the other down into the barrel, then repeat with the other socket At the very least you will often be able to identify which of the wires is bad (which may or may not help much in the long run).

Finally, before committing yourself to rewiring, carefully take the entire weapon apart and test everything one more time with one probe clipped directly to the wire (make sure that you first remove any insulation from the wire) and the other probe sticking down into the barrel. If you don't see any signs of life at this point then rewiring is probably your only remaining option.

[Stormbringer]

So, I tried out testing with the multimeter, and initially found both wires to be intermittently conductive. Closer inspection, however, revealed that one of the wires had separated from its contact pin and was held to the cup by the silk insulation.