Cautions To Observe When Troubleshooting - Thermador CM301B Service Manual

CM Oven Service Manual

CAUTIONS TO OBSERVE WHEN TROUBLESHOOTING

Unlike many other appliances, the microwave oven is high-voltage, high-current equipment.
Although it is free from danger in ordinary use, extreme care should be taken during repair.
Remove your wristwatch when working close to or when
replacing the magnetron.
1. Check the grounding. The microwave oven is designed to be used when grounded. Make sure
it is grounded properly before beginning repair work.
2. Discharge the electric charge in the high-voltage capacitor. For about 30-seconds after the
oven stops, an electric charge remains in the high-voltage capacitor. When replacing or
checking parts, short between the oven chassis and the terminal of the high-voltage capacitor
(terminals of lead wire from magnetron filament, high-voltage transformer filament lead
wire, and diode lead wire) with an insulated screwdriver to discharge.
There is high-voltage present, with high current capabili-
ties, in the circuits of the high-voltage winding and fila-
ment winding of the high-voltage transformer. It is ex-
tremely dangerous to work on or near these circuits with
the oven energized.
Do not measure the voltage in the high-voltage circuit,
including the filament voltage of the magnetron.
Never touch any circuit wiring with your hand or with an
insulated tool during operation.
3. When parts must be replaced, disconnect the power to the unit.
4. Avoid inserting nails, wire, etc. through any holes in the unit during operation. Never insert
a wire, nail, or any other metal object through the lamp holes on the cavity or any other holes
or gaps, because such objects may work as an antenna and cause microwave leakage.
5. Confirm after repair. After repairing or replacing parts, make sure that the screws of the oven,
etc., are neither loose or missing. Microwaves might leak if screws are not properly tightened.
6. Make sure that all electrical connections are tight.
7. Check for microwave energy leakage. Refer to "Measuring For Microwave Radiation Leak-
age" on Page 6.
CAUTION
WARNING
Page 4
Lit. No. 94-30-006B