LG 32LW4500, Руководство по обслуживанию

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LG 32LW4500 Service Manual
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IC Remove/Replacement IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong) through Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the
which the IC leads are inserted and then bent flat against the
circuit foil. When holes are the slotted type, the following technique
circuit foil. When holes are the slotted type, the following technique
should be used to remove and replace the IC. When working with
should be used to remove and replace the IC. When working with
boards using the familiar round hole, use the standard technique
boards using the familiar round hole, use the standard technique
as outlined in paragraphs 5 and
as outlined in paragraphs 5 and 6 above. 6 above.
Removal Removal
1. 1. Desolder and straighten eac Desolder and straighten each IC lead in one operation by h IC lead in one operation by gently gently
prying up on the lead with the soldering iron tip as the solder prying up on the lead with the soldering iron tip as the solder
melts.
melts.
2. Draw away the melted solder with an anti-static suction-type 2. Draw away the melted solder with an anti-static suction-type
solder removal device (or with solder braid) before removing the solder removal device (or with solder braid) before removing the
IC.
IC.
Replacement Replacement
1. 1. Carefully insert the repla Carefully insert the replacement IC in the circuit cement IC in the circuit board. board.
2. Carefully bend each IC lead against the circuit foil pad and 2. Carefully bend each IC lead against the circuit foil pad and
solder it. solder it.
3. 3. Clean the soldered areas wi Clean the soldered areas with a small wire-bristle brus th a small wire-bristle brush. h.
Circuit Board Foil Repair Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to separate from or "lift-off" the board. The
board causing the foil to separate from or "lift-off" the board. The
following guidelines and procedures should be followed whenever
following guidelines and procedures should be followed whenever
this condition is encountered.
this condition is encountered.
At IC Connections At IC Connections
To repair a defective copper pattern at IC connections use the To repair a defective copper pattern at IC connections use the
following procedure to install a jumper wire on the copper pattern
following procedure to install a jumper wire on the copper pattern
side of the circuit board. (Use this technique only on IC
side of the circuit board. (Use this technique only on IC
connections).
connections).
1. Carefully remove the damaged copper pattern with a sharp 1. Carefully remove the damaged copper pattern with a sharp
knife. (Remove only as much copper as absolutely necessary). knife. (Remove only as much copper as absolutely necessary).
2. carefully scratch away the solder resist and acrylic coating (if 2. carefully scratch away the solder resist and acrylic coating (if
used) from the end of the remaining copper pattern. used) from the end of the remaining copper pattern.
3. 3. Bend a small "U" in one end of a small ga Bend a small "U" in one end of a small gauge jumper wire and uge jumper wire and
carefully crimp it around the IC pin. carefully crimp it around the IC pin. Solder the IC connection. Solder the IC connection.