Precaution; Safety Precautions - Samsung SMH7174WE Service Manual

1. Precaution

Follow these special safety precautions. Although the microwave oven is completely safe during ordinary use,
repair work can be extremely hazardous due to possible exposure to microwave radiation, as well as potentially
lethal high voltages and currents.

1-1 Safety precautions (

1. All repairs should be done in accordance with the
procedures described in this manual. This product
complies with Federal Performance Standard 21
CFR Subchapter J(DHHS).
2. Microwave emission check should be performed
to prior to servicing if the oven is operative.
3. If the oven operates with the door open :
Instruct the user not to operate the oven and
contact the manufacturer and the center for devices
and
radiological health immediately.
4. Notify the Central Service Center if the
microwave leakage exceeds 5 mW/cm
5. Check all grounds.
6. Do not power the MWO from a "2-prong"
AC cord. Be sure that all of the built-in
protective devices are replaced. Restore any
missing protective shields.
7. When reinstalling the chassis and its
assemblies, be sure to restore all protective
devices, including: nonmetallic control
knobs and compartment covers.
8. Make sure that there are no cabinet openings
through which people --particularly children
--might insert objects and contact dangerous
voltages. Examples: Lamp hole,ventilation slots.
9. Inform the manufacturer of any oven foundto
have emission in excess of 5 mW/cm
repairs to bring the unit into compliance at no cost
to owner and try to determine cause.
Instruct owner not to use oven until it has been
brought into compliance.
CENTRAL SERVICE CENTER
10. Service technicians should remove their watches
while repairing an MWO.
)
11. To avoid any possible radiation hazard,replace
parts in accordance with the wiring diagram. Also,
use only the exact replacements for the following
parts: Primary and secondary interlock switches,
interlock monitor switch.
12. If the fuse is blown by the Interlock Monitor Switch:
Replace all of the following at the same time:
Primary, door sensing switch and power relay, as
well as the Interlock Monitor Switch. The correct
adjustment of these switches is described
elsewhere in this manual. Make sure that the fuse
has the correct rating for the particular model being
repaired.
. 13. Design Alteration Warning:
2
Use exact replacement parts only, i.e.,only those
that are specified in thedrawings and parts lists
of this manual. This is especially important for the
Interlock switches, described above. Never alter
or add to the mechanical or electrical design of the
MWO. Any design changes or additions will void
the manufacturer's warranty. Always unplug the
unit's AC power cord from the AC power source
before attempting to remove or reinstall any
component or assembly.
14. Never defeat any of the B+ voltage interlocks.
Do not apply AC power to the unit (or any of its
assemblies) unless all solid-state heat sinks are
correctly installed.
15. Some semiconductor ("solid state") devices are
easily damaged by static electricity. Such
components are called Electrostatically Sensi-
,Make tive Devices (ESDs). Examples include integrated
2
circuits and field-effect transistors. Immediately
before handling any semiconductor components
or assemblies, drain the electrostatic charge from
your body by touching a known earth ground.
16. Always connect a test instrument's ground lead to
the instrument chassis ground before connecting
the positive lead; always remove the instrument's
ground lead last.
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