Akai LEA-19A08G, Service Manual

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Replacement
Replacement Replacement
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. (It is not necessary to reapply acrylic coating to the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
Removal/Replacement Removal/Replacement
Removal/Replacement
1. Remove the defective transistor by clipping its leads as close as possible to the component body.
2. Bend into a "U" shape the end of each of three leads remaining on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. Connect the replacement transistor leads to the corresponding leads extending from the circuit board and crimp the "U" with
long nose pliers to insure metal to metal contact then solder each connection.
Power Power Power Power Output, Output, Output, Output, Transistor Transistor Transistor Transistor Device Device Device Device
Removal/Replacement
Removal/Replacement
Removal/Replacement Removal/Replacement
1. Heat and remove all solder from around the transistor leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the circuit board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Diode Diode Diode Removal/Replacement Removal/Replacement Removal/Replacement Removal/Replacement
1. Remove defective diode by clipping its leads as close as possible to diode body.
2. Bend the two remaining leads perpendicular y to the circuit board.
3. Observing diode polarity, wrap each lead of the new diode around the corresponding lead on the circuit board.
4. Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder joints of the two "original" leads. If they are not shiny, reheat them and if
necessary, apply additional solder.
Fuse Fuse Fuse Fuse and and and and Conventional Conventional Conventional Conventional Resistor Resistor Resistor Resistor
Removal/Replacement
Removal/Replacement Removal/Replacement
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board hollow stake.
2. Securely crimp the leads of replacement component around notch at stake top.
3. Solder the connections.
CAUTION: CAUTION: CAUTION: CAUTION: Maintain original spacing between the replaced component and adjacent components and the circuit board to
prevent excessive component temperatures.
Circuit Circuit Circuit Circuit Board Board Board Board Foil Foil Foil Foil Repair Repair Repair 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 At At At IC IC IC IC Connections Connections Connections 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