This article is from the Fencing FAQ, by Morgan Burke with numerous contributions by others.
Weapon fails weight test.
1) The spring is too soft.
2) Friction between the barrel and point is overwhelming the
3) Too much tape on the end of your blade is jamming
against the hole in the weight.
Hitting the strip produces a light.
1) The strip is not grounded, or is dirty/corroded.
2) The exterior of the foil point is dirty/corroded.
Valid touch produces a white light.
1) Opponent's lame' is not connected.
2) Opponent's body wire is broken. Diagnose by testing at the
lame' clip and at the reel wire connection.
3) Opponent's lame' has a dead spot. With some boxes, dead spots
can be diagnosed by grounding the fencer's weapon to his
suspect lame', and then probing the lame' with the other
fencer's weapon. This does not work with boxes that have an
4) Your foil body wire polarity is reversed.
5) The exterior of your foil point is dirty/corroded.
6) Foil circuit is breaking just before the touch (see below).
Foil produces white lights when the tip is not depressed.
1) The tip is jammed shut.
2) Grit in the tip is breaking the circuit.
3) The barrel is loose.
4) The foil wire is broken. If the lights are intermittent, try
flexing the blade to trigger the white lights; success means
the blade wire is probably broken. If the lights are
triggered by shaking the blade, the point or clip may be to
5) The body wire is insecurely clipped to the weapon.
6) The body wire is broken. Diagnose by shorting the two
connections on the weapon end of the body wire. If the lights
continue, the body wire or reel is at fault. Short the two
close prongs at the other end of the body wire; if the lights
stop, the body wire is to blame. If not see (7).
7) The scoring apparatus is broken. The connections, reel wire,
reel contacts, floor wire, or scoring box may be at fault.
Short the same wires as in (6) at the various points of
connection to successively eliminate each.
8) The pommel is loose.
Foil produces coloured lights when the tip is not depressed but
is in contact with the opponent's lame'.
1) The circuit is broken; see previous problem.
2) The circuit is breaking when the blade flexes as it contacts
the lame' or when the point is jarred. Could be caused by
grit in the tip, a broken wire whose ends normally remain in
contact, or a separated wire and cup.
3) The box is on the wrong weapon setting.
There is no light when a touch is made.
1) You are not hitting properly.
2) Friction between the barrel and point is preventing the
point from depressing.
3) Spring is too heavy.
4) Opponent is grounding his weapon to his lame'.
5) You are grounding your own foil to your opponent's lame'.
Improve the insulation on your foible (15 cm is required).
6) The foil wire is shorting to the weapon. Check the integrity
of the insulation along the wire and beneath the cushion.
Also make sure no wire ends at the clip are touching the rest
of the weapon.
7) The scoring box is on the wrong weapon setting.
8) There is a short in your body wire. If there are no lights
when the weapon is unplugged, but there are lights when the
body wire is unplugged from the reel, the body wire is at
9) There is a short in the scoring apparatus. If there are no
lights when the fencer unplugs from the reel, this is the
problem. It can be isolated by successively unplugging
connections to the box.
Wrong lights go off when a touch is made.
1) The scoring box is on the wrong weapon setting.
2) The floor wires are reversed.