SAMSUNG M187DNR, PG113UR, G2739NR, PG83R Service Manual

PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE ENERGY

(a) Do not operate or allow the oven to be

operated with the door open.

(b) Make the following safety checks on

all ovens to be serviced before activating
the magnetron or other microwave
source, and make repairs as necessary:
(1) Interlock operation,
(2)properdoorclosing,
(3) seal and sealing surfaces (arcing,

wear, and other damage),

(4) damage to or loosening of hinges

and latches.

(5) evidence of dropping or abuse.

(c) Before turning on microwave power

for any service test or inspection within
the microwave generating
compartments, check the magnetron,
wave guide or transmission line, and
cavity for proper alignment, integrity,
and connections.

(d) Any defective or misadjusted

components in the interlock, monitor,
door seal, and microwave generation
and transmission systems shall be
repaired, replaced, or adjusted by
procedures described in this manual
beforetheovenisreleasedtothe
owner.

(e) A microwave leakage check to verify

compliance with the Federal
performance standard should be
performed on each oven prior to
release to the owner.

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,besuretorestoreallprotective
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 emission in excess of 5 mW/cm
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.

CENTRAL SERVICE CENTER

10. Service technicians should remove their
watches while repairing an MWO.

2

2

,

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: Secondary, 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:
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, 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
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.

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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