Sharp R-662WM Service Manual ▷ View online
COMMON BREAKDOWN AND MEANS OF REPAIRING
PHENOMENON CAUSE REPAIRING
MEANS
1.When starting the
oven, the lamp is not on,
the turntable tray can’t
rotate and the food can’t
be heated
1. fuse
broken
2. The primary and secondary winding of the
transformer are short-circuited.
3. The earthing or the polarity of the capacitor is
punctured.
4. The pilot switch can’t cut off.
5. The interlock switch hasn’t closed.
6. The power plug and the socket are not in good
5. The interlock switch hasn’t closed.
6. The power plug and the socket are not in good
connection.
7. The door hook broken.
1. Change a new fuse.
2.
2.
Change a new
transformer.
transformer.
3. Change a new capacitor.
4. Change a new pilot
4. Change a new pilot
switch.
5. Change a new interlock
switch.
6. Adjust the connection or
replace it by a new one.
7. Change a new book.
2.When starting the
oven, the lamp is on, the
turntable rotating, the fan
cycling but the food can’t
be heated.
oven, the lamp is on, the
turntable rotating, the fan
cycling but the food can’t
be heated.
1. The primary and secondary winding, the
filament of the transformer are open-circuited.
2. The magnetron filament is open-circuited, the
magnetic steel of the magnetron broken or the
magnetron is air leaking.
magnetron is air leaking.
3. Time and power distributor broken..
4. The plugs of the magnetron of the capacitor
4. The plugs of the magnetron of the capacitor
loosed.
1.
Change a new
transformer.
transformer.
2. Change the magnetron.
3. Change the time power
3. Change the time power
distributor or the micro-
switch.
switch.
4. Fix
them.
3.The food can be
heated, but the lamp is
not on.
heated, but the lamp is
not on.
1. The lamp broken.
2. The plug fall off.
2. The plug fall off.
1. Change a new lamp
2. Insert the plug again
2. Insert the plug again
4.The food can be
heated but the turntable
tray is not rotating.
heated but the turntable
tray is not rotating.
1. The turntable motor broken
2. The plug fall off
3. Connecting shaft weave broken
2. The plug fall off
3. Connecting shaft weave broken
1. Change the turntable
motor
2. Insert the plug securely
3. Change the weave
3. Change the weave
5.The oven can heat
within 2-3 minutes, but
can not heat from the
fourth minutes.
within 2-3 minutes, but
can not heat from the
fourth minutes.
1. The winding of the fan motor in open-circuited.
2. The fan falls off
3. The plug of the fan motor falls off
4. The turntable shaft is griped with the motor
2. The fan falls off
3. The plug of the fan motor falls off
4. The turntable shaft is griped with the motor
bearing.
5. The cooling vent blocked
1. Change the fan motor
2. Change the fan
3. Insert the plug
4. Overhauling
2. Change the fan
3. Insert the plug
4. Overhauling
them
5. Repairing
it
6.When starting the
oven, it can’t heat, and
with “wenwen” noise
oven, it can’t heat, and
with “wenwen” noise
The high voltage diode was punctured
Change a new diode
7.The oven can heat,but
with sound “shishi” noise
with sound “shishi” noise
The iron core of the transformer loosed
Change a new transformer
8.Large amount of
microwave leakage
microwave leakage
1. The door deformed
2. The door metal net cracked
3. The gap of the door crack is too large
4. The welding point of the oven fall off
5. The screws which fix the magnetron loosed
6. The wave guide connection oxidized
7. The magnetron copper filament washer is too
2. The door metal net cracked
3. The gap of the door crack is too large
4. The welding point of the oven fall off
5. The screws which fix the magnetron loosed
6. The wave guide connection oxidized
7. The magnetron copper filament washer is too
thin cause the wave guide opening not in good
earth.
earth.
1. Mend the door
2. Change the door
3. Adjust the gap
4. Change the oven
5. Tighten the screws
6. Scrape the oxidized and
2. Change the door
3. Adjust the gap
4. Change the oven
5. Tighten the screws
6. Scrape the oxidized and
tighten the screws
7. Thick the copper filament
washer
9.The door can’t open
1. After long time using, the wear and the rust-
eaten enlarged the gap of the door shaft and
the shaft hole, thus cause the door crooked.
the shaft hole, thus cause the door crooked.
2. The door hook broken
1. Adjust the hinge to rectify
the position of the door.
2. Change the hook
10.The door release
button fall off
button fall off
Wore aged after long time operating
Overhaul it or renew it
11.Electricity leaking
The earthing insulation resistances of all the
motors or the transformer are less than 2 mega
ohm.
motors or the transformer are less than 2 mega
ohm.
Test where is the leaking
place, then repair it or
change those damaged
components.
place, then repair it or
change those damaged
components.
5-9
IMPORTANT THINGS TO DO PRIOR TO CRITICAL PART
SERVICING
The following instructions are CRITICAL to the owner’s safety. Be sure to follow all the instructions. Contact the
manufacturer of distributor if you have any question.
1.1 If the oven is operative prior to servicing a Microwave Leakage Test (Microwave Emission Check) should be
performed prior to servicing the oven.
1.2 in the event that any microwave oven found to have microwave emission level in excess of 1 mW/cm
2
.The
following procedures should be followed:
a. Inform the distributor, importer, or manufacture the finding. Record it in the logbooks well.
b. Repair the unit at no cost to the owner.
c. Investigate the oven and ascertain the cause of the excessive leakage.
d. Hold the oven in your facility and instruct the owner not to use the unit until the oven has been brought into
compliance.
1.3 In the event that the oven operates with the door open. The following procedures should be followed:
a. Tell the user not to operate the oven.
b. Hold the oven in your facility until it is investigated and repaired.
c. Contact the manufacturer immediately.
2. Interlock Assembly Replacement and Adjustment
2.1
If you suspect defective primary, secondary or monitor interlock switches, use your ohmmeter(digital or analog
type the check the electrical continuity.
2.2
Make sure the power cord is pulled out and the high-voltage capacitor is discharged before the electrical
continuity check.
2.3
Set the ohmmeter to “Low Resistance” range and connect both leads (alligator clips) to the switch terminals.
2.4
Open the door and notice the meter reading. The primary or secondary interlock switch should show an “infinite”
resistance when the door is open. Replace it when it is defective. The monitor interlock should show a “zero or
near zero” resistance when the door is open. When the door is closed, the readings will be opposite.
2.5
If the oven has been received inoperative due to the failure of the monitored safety(primary and/or secondary)
interlock(s),you should replace all of the monitored safety interlock switched and the monitor switch.
3. Door and Hinge Replacement and Adjustment
3.1
Pull the power cord from the outlet. Check the door for warped or damaged areas. Check the hinges for broken
or worn areas. Check other areas such as cracked from glass, broken door latched, worn/cracked viewing
screen and etc.
3.2
After determining the door assembly should be replaced, check the parts list for the correct part number. All oven
door components must be ordered directly from the manufacturer or its authorized distributor.
4. Magnetron
Replacement
4.1
Check for the presence of the wire mesh gasket before installation.
4.2
Conduct a Microwave Leakage Test at the magnetron area prior to installing the top cover.
5-10
SAFETY CHECKS AND TESTS AFTER SERVING
Constructional Checks
If mechanical or electrical(electronic) parts have been replaced be sure to follow the following steps.
1.1
Check for correct wiring, adequate mechanical decrements of parts, and firm connectors.
1.2
Check for adequate grounding.
1.3
Check the following items before turning the oven ON.
1)
Proper door closing, seal/choke surfaces, and hinges.
2)
No outer case damage.
3)
Proper interlock and monitor operations.
Insulation Resistance Test
If the low voltage power supply has been repaired, use a 500 V Mega ohmmeter to measure the resistance between the
primary(Line and Neutral)of the power plug and operator accessible metal parts. The resistance should be no less than 2 Mega
Ohms. Repair the oven again when necessary.
5-11
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