Repairing Printed Circuit Wiring

TM 11-5820-765-34

Repairing Printed Circuit Wiring

Use only a pencil-type soldering iron with a maximum rating of 25 watts.

Excessive heat will cause printed wiring conductors to separate from the

board. For additional soldering techniques, refer to TB SIG 222.

Repair printed circuit wiring that has a crack, pinhole, cut, or notch more than 30 percent of the

wire's width.

Procedure:

Remove protective coating.

Place a short length of flat bus wire over the defective wiring and hold it firmly in place.

Solder the entire length of bus wire to the wiring.

Do not apply heat longer than needed. Prolonged heat can separate the con-

ductor from the card; this damage cannot be repaired.

Apply protective coating to exposed area after completing repairs.

Replacing Defective Parts

Remove defective part:

Cut leads on part between part and circuit card mounting holes.

Cut leads as close to mounting holes as possible.

Remove protective coating around the part on the card's printed wiring side.

Heat printed wiring at mounting holes with soldering iron until solder melts.

Remove excess solder and remaining pieces of wire leads.

Do not apply heat longer than needed. Prolonged heat can separate the

printed wiring from the card, which will damage the care.

Bend the leads of replacement part to fit mounting holes.

Insert leads in mounting holes from parts side of card; press part firmly against card.

On card's wiring side, cut leads of part; leave approximately 1/8 inch of leads protruding

from card.

Bend and press these leads against printed circuit conductor

Using a heat sink, solder replacement part leads to printed circuit conductor.

Apply protective coating to repaired area.

3-9