Service manual

1
Samsung Electronics
1. Precaution
1-1 Safety precautions ( )
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. All repairs should be done in accordance
with the procedures described in this
manual.
2. Microwave emission check should be
performed 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 centre for
devices and radiological health immediately.
4. Notify the Central Service Centre if the
microwave leakage exceeds 5 mW/cm
2
.
5. Check all grounds.
6. Do not power the microwave oven 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 found
to have emmission in excess of 5mW/cm
2
.
Make 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.
10. Service technicians should remove their
watches while repairing an microwave oven.
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 door sensing 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 and door sensing
switches, 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:
Use exact replacement parts only, i.e.,
only those that are specified in the
drawings and parts lists of this manual.
This is especially important for the
Interlock switches. Never alter or add to
the mechanical or electrical design of the
microwave oven. Any design changes or
additions will void the manufacturer's
warranty.
14. Always unplug the unit's AC power cord
from the AC power source before
attempting to remove or reinstall any
component or assembly.
15. 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.
16. Some semiconductor ("solid state") devices
are easily damaged by static electricity.
Such components are called
Electrostatically Sensitive Devices (ESDs).
Examples include integrated 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.
17. 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.
18.When checking the continuity of the switches
or transformer, always make sure that the
power is OFF, and one of the lead wires is
disconnected.
19. Components that are critical for safety are
indicated in the circuit diagram or parts
list by shading, or .
20. 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.