Special Servicing Precautions (Continued); Special High Voltage Precautions; Specifications - Samsung SMH7174WE Service Manual

1-2 Special Servicing Precautions (Continued)

17. When checking the continuity of the witches or transformer,
always make sure that the power is OFF, and one of the
lead wires is disconnected.
18. Components that are critical for safety are indicated in the
circuit diagram by shading,
19. Use replacement components that have the same ratings,
especially for flame resistance and dielectric strength specifications.
A replacement part that does not have the same safety characteristics
as the original might create shock, fire or other hazards.
NOTE : Connect the oven to a 20A. When connecting the oven to a
15A,make sure that circuit breaker can operate.

1-3 Special High Voltage Precautions

1. High Voltage Warning Do not attempt to
measure any of the high voltages --this includes
the filament voltage of the magnetron. High
voltage is present during any cook cycle.
Before touching any components or wiring,
always unplug the oven and discharge the high
voltage capacitor (See Figure 1-1)
2. The high-voltage capacitor remains charged
about 30 seconds after disconnection. Short the
negative terminal of the high-voltage capacitor to
to the oven chassis. (Use a screwdriver.)
3. High voltage is maintained within specified limits
by close-tolerance, safety-related components
and adjustments. If the high voltage exceeds the
specified limits, check each of the special
components.
PRECAUTION
There exists HIGH VOLTAGE ELECTRICITY with
high current capabilities in the circuits of the HIGH
VOLTAGE TRANSFORMER secondary and fila-
ment terminals. It is extremely dangerous to work
on or near these circuits with the oven energized.
DO NOT measure the voltage in the high voltage
circuit including filament voltage of magnetron.
or .
- 2 -
High Voltage Capacitor
Fig. 1-1 Discharging High Voltage Capacitor
PRECAUTION
Never touch any circuit wiring with your hand nor
with uninsulated tool during operation.
PRECAUTION
Servicemen should remove their watches when-
ever working close to or replacing the magnetron.