Daewoo 901D Service Manual page 7

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 end 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 insoure metal-to-metal contact, then solder each connection.
Power IC, Transistor or Devices Removal/Replacement
1. Heat and remove all solders from the device leads.
2. Remove the heatsink mounting screw (if applicable).
3. Carefully remove the device from the circuit board.
4. Insert new device in circuit board.
5. Solder each device lead, and clip off excess lead.
6. Replace heatsink.
FIGURE 1. USE SOLDERING IRON TO PRY LEADS
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