When measuring voltage, wrap tin foil around the top of the negative probe. Then press the foil against the wire with your finger.
Attach probe circuit tester (in Volt range) to middle portion of each filament.
If a filament is burned out, circuit tester registers 0 or battery voltage.
To locate burned out point, move probe to left and right along filament. Test needle will swing abruptly when probe passes the point.
REPAIR
REPAIR EQUIPMENT
Conductive silver composition (Dupont No. 4817 or equivalent)
Ruler 30 cm (11.8 in) long
Drawing pen
Heat gun
Alcohol
Cloth
REPAIRING PROCEDURE
Wipe broken heat wire and its surrounding area clean with a cloth dampened in alcohol.
Apply a small amount of conductive silver composition to tip of drawing pen. Shake silver composition container before use.
Place ruler on glass along broken line. Deposit conductive silver composition on break with drawing pen. Slightly overlap existing heat wire on both sides [preferably 5 mm (0.20 in) ] of the break.
After repair has been completed, check repaired wire for continuity. This check should be conducted 10 minutes after silver composition is deposited. Do not touch repaired area while test is being conducted.
Apply a constant stream of hot air directly to the repaired area for approximately 20 minutes with a heat gun. A minimum distance of 3 cm (1.2 in) should be kept between repaired area and hot air outlet. If a heat gun is not available, let the repaired area dry for 24 hours.
