LG FLATRON W1943SB Service Manual page 7

Circuit Board Foil Repair
Excessive heat applied to the copper foil of any
printed 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 following guidelines
and procedures should be followed whenever this
condition is encountered.
At IC Connections
To repair a defective copper pattern at IC connections
use the following procedure to install a jumper wire
on the copper pattern side of the circuit board.
(Use this technique only on IC connections).
1. Carefully remove the damaged copper pattern with
a sharp knife. (Remove only as much copper
as absolutely necessary).
2. carefully scratch away the solder resist and
acrylic coating (if used) from the end of the
remaining copper pattern.
3. Bend a small "U" in one end of a small gauge
jumper wire and carefully crimp it around the IC pin.
Solder the IC connection.
4. Route the jumper wire along the path of the out-
away copper pattern and let it overlap the previously
scraped end of the good copper pattern. Solder the
overlapped area and clip off any excess jumper wire.
Copyright ©2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
At Other Connections
Use the following technique to repair the defective
copper pattern at connections other than IC Pins. This
technique involves the installation of a jumper
wire on the component side of the circuit board.
1. Remove the defective copper pattern with a
sharp knife.
Remove at least 1/4 inch of copper, to ensure that
a hazardous condition will not exist if the jumper
wire opens.
2. Trace along the copper pattern from both sides of
the pattern break and locate the nearest component
that is directly connected to the affected copper
pattern.
3. Connect insulated 20-gauge jumper wire from the
lead of the nearest component on one side of the
pattern break
component on the other side.
Carefully crimp and solder the connections.
CAUTION: Be sure the insulated jumper wire
is dressed so the it does not touch components or
sharp edges.
7
LGE Internal Use Only
to the lead of the nearest