Haier 21F99, Руководство по обслуживанию

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2. Securely crimp the leads of replacement component around notch at stake top.
3. Solder the connections
Caution: Maintain original spacing between the replaced component and adjacent
components and the circuit board to prevent excessive component temperatures.
Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit board will weaken the adhesive
that bonds 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.
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 insure 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 to the lead of the nearest component on the other side.
Carefully crimp and solder the connections.
Caution: Be sure the insulated jumper wire is dressed so that it does not touch
components or sharp edges.