Component Replacement And Adjustment Procedure - Sharp R-308JK Service Manual

PRECAUTIONS FOR USING LEAD-FREE SOLDER
1. Employing lead-free solder
The "Main PWB" of this model employs lead-free solder. This is indicated by the "LF" symbol printed on the PWB and in the
service manual. The suffix letter indicates the alloy type of the solder.
Example:
2. Using lead-free wire solder
When repairing a PWB with the "LF" symbol, only lead-free solder should be used. (Using normal tin/lead alloy solder may
result in cold soldered joints and damage to printed patterns.)
As the melting point of lead-free solder is approximately 40˚C higher than tin/lead alloy solder, it is recommend that a dedicated
bit is used, and that the iron temperature is adjusted accordingly.
3. Soldering
As the melting point of lead-free solder (Sn-Ag-Cu) is higher and has poorer wettability, (flow), to prevent damage to the land
of the PWB, extreme care should be taken not to leave the bit in contact with the PWB for an extended period of time. Remove
the bit as soon as a good flow is achieved. The high content of tin in lead free solder will cause premature corrosion of the
bit. To reduce wear on the bit, reduce the temperature or turn off the iron when it is not required.
Leaving different types of solder on the bit will cause contamination of the different alloys, which will alter their characteristics,
making good soldering more difficult. It will be necessary to clean and replace bits more often when using lead-free solder.
To reduce bit wear, care should be taken to clean the bit thoroughly after each use.

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result
in severe, possibly fatal, electric shock.
(Example)
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Avoid possible exposure to microwave energy. Please follow the instructions below before
WARNING:
operating the oven.
1. Disconnect the power supply cord.
2. Make sure that a definite" click" can be heard when the
microwave oven door is unlatched. (Hold the door in a
closed position with one hand, then push the door open
button with the other, this causes the latch leads to rise, it
is then possible to hear a "click' as the door switches
operate.)
3. Visually check the door and cavity face plate for damage
(dents, cracks, signs of arcing etc.).
Carry out any remedial work that is necessary before operat-
ing the oven.
Do not operate the oven if any of the following conditions exist;
1. Door does not close firmly.
Sn-Ag-Cu
Indicates lead-free solder of tin, silver and copper.
WARNING AGAINST HIGH VOLTAGE:
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal is damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective parts in the microwave generating
and transmission assembly.
7. There is visible damage to the oven.
Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
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R-308JK
R- 308JS
R-308JW
R-309JW