Daewoo 719BF Service Manual download pdf (Page 7)

FIGURE 1. USE SOLDERING IRON TO PRY LEADS

◆ IC Removal/Replacement

Some utilized chassis circuit boards have slotted (oblong) holes through which the IC leads are inserted

and then bent flat against the circuit foil. When holes are slotted, the following technique should be used

to remove and replace the IC. When working with boards using the familiar round hole, use the standard

technique as outlined in paragraphs 5 on the page under the title of general soldering guidelines.

◆ Removal

1. Desolder and straighten each IC lead in one operation by gently prying up on the lead with the

soldering iron tip as the solder melts.

2. Draw away the melted solder with an anti-static suction-type solder removal device (or with

desoldering braid before removing the IC.

◆ Replacement

1. Carefully insert the replacement IC in the circuit board.

2. Carefully bend each IC lead against the circuit foil pad and solder it.

3. Clean the soldered areas with a small wire-bristle brush. (lt is not necessary to reapply acrylic coating

to the area).

◆ “Small-Signal” Discrete Transistor Removal/Replacement

1. Remove the defective transistor by clipping its leads as close as possible to the component body.

2. Bend the ends of each of three leads remaining on the circuit board into a “U” shape.

3. Bend the replacement transistor leads into a “U” shape.

4. Connect the replacement transistor leads to the corresponding leads extending from the circuit board

and crimp the “U” with long nose pliers to ensure metal-to-metal contact, then solder each connection.

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Daewoo 719BF Service Manual Page 7