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SOI  03.06  FV 

5/38 

599 36 78-45 

 

 

SERVICING 

 

WARNING TO SERVICE PERSONNEL

 

 

 

 

Microwave ovens contain circuitry capable of producing very high voltage and current. 
Contact with the following parts will result in electrocution 
High voltage capacitor, High Voltage transformer, Magnetron, High voltage rectifier assembly, 
High voltage wires.

 

 

  REMEMBER TO CHECK 3D 

  1) Disconnect the supply. 
  2) Door opened, and wedged open. 

  3) Discharge high voltage capacitor. 

 

WARNING AGAINST THE CHARGE OF THE 
HIGH VOLTAGE CAPACITOR 

The high-voltage capacitor remains charged about 
60seconds after the oven has been switched off. 
Wait for 60 seconds and then short-circuit the 
connection of the high-voltage capacitor (that is, of 
the connecting lead of the high-voltage rectifier) 
against the chassis with the use of an insulated 
screwdriver.

 

It is recommended that wherever possible fault-
finding is carried out with the supply disconnected. It 
may in, some cases, be necessary to connect the 
supply after the outer case has been removed, in this 
event carry out 3D checks and then disconnect the 
leads to the primary of the power transformer. Ensure 
that these leads remain isolated from other 
components and the oven chassis. (Use insulation 
tape if necessary.) When the testing is completed 
carry out 3D checks and reconnect the leads to the 
primary of the power transformer.

 

 

REMEMBER TO CHECK 4R 

1) Reconnect all leads removed from components 
 during 

testing. 

2) Replace the outer case (cabinet). 
3) Reconnect the supply. 
4) Run the oven. Check all functions.

 

 
 

Microwave ovens should not be run empty. To test for 
the presence of microwave energy within a cavity, 
place a cup of cold water on the oven turntable, close 
the door and set the power to HIGH and set the 
microwave timer for two (2) minutes. When the two 
minutes has elapsed (timer at zero) carefully check 
that the water is now hot. If the water remains cold 
carry out 3D checks and re-examine the connections 
to the component being tested.

 

 
 

When all service work is completed, and the oven is 
fully assembled, the microwave power output should 
be checked and a microwave leakage test carried out.

 

 

 

 

When troubleshooting the microwave oven, it is 
helpful to follow the Sequence of Operation in 
performing the checks. 
Many of the possible causes of trouble will require 
that a specific test be performed. These tests are 
given a procedure letter which will be found in the 
"Test Procedure" section.

 

 

IMPORTANT: 

If the oven becomes inoperative 
because of a blown fuse F1 in the 
monitored latch switch - monitor 
switch - circuit, check the monitored 
latch switch and monitor switch and 
before replacing the fuse F1.

 

 

GENERAL INFORMATION

 

 

WARNING 

THIS APPLIANCE MUST BE EARTHED 

 

IMPORTANT 

 

THE WIRES IN THIS MAINS LEAD ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING 
CODE: 
 GREEN-AND-YELLOW 

 

EARTH 

 BLUE 

 

NEUTRAL 

 BROWN 

 

LIVE

 

 

 

As part of our policy of continuous improvement, we reserve the right to 
alter design and specifications without notice

 

 
 
 

Содержание EMS2685

Страница 1: ...CTS Corso Lino Zanussi 30 Publication No I 33080 PORCIA PN ITALY 599 36 78 45 Tel 39 0434 394850 Fax 39 0434 394096 SOI Edition 03 2006 EN SERVICE FV Microwave Oven Middle Grill MCD2660E EU MCD2661E EU MCD2660E UK EMS2685 EU EMS2685 UK ZM266ST UK JMW9161 A D MO926G I MOA4226 D K ...

Страница 2: ...SOI 03 06 FV 2 38 599 36 78 45 ...

Страница 3: ...5 PRODUCT SPECIFICATIONS 6 APPEARANCE VIEW 7 OPERATING SEQUENCE 13 FUNCTION OF IMPORTANT COMPONENTS 15 TROUBLESHOOTING CHART 17 TEST PROCEDURE 18 CONTROL PANEL ASSEMBLY 26 SERVICING 27 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE 28 MICROWAVE MEASUREMENT 34 TEST DATA A GLANCE WIRING RE WIRING 35 SCHEMATIC DIAGRAMS 36 PICTORIAL DIAGRAM 38 ...

Страница 4: ...mation It is recommended that service engineers carefully study the entire text of this manual so they will be qualified to render satisfactory customer service WARNING Note The parts marked are used at voltage more than 250V Schematic Diagrams WARNING Never operate the oven until the following points are ensured A The door is tightly closed B The door and oven hinges are not defective C The door ...

Страница 5: ... Reconnect all leads removed from components during testing 2 Replace the outer case cabinet 3 Reconnect the supply 4 Run the oven Check all functions Microwave ovens should not be run empty To test for the presence of microwave energy within a cavity place a cup of cold water on the oven turntable close the door and set the power to HIGH and set the microwave timer for two 2 minutes When the two ...

Страница 6: ...Width 342mm Height 207mm Depth 368mm Turntable diameter 325mm Clock 1 00 12 59 or 0 00 23 59 12HR or 24HR setting Timer 0 99 minutes 90 seconds Microwave Power for Variable Cooking Repetition Rate 100P Full power throughout the cooking time 70P approx 70 of Full Power 50P approx 50 of Full Power 30P approx 30 of Full Power 10P approx 10 of Full Power Stir TIMER WEIGHT PORTION button AUTO COOK butt...

Страница 7: ...points 4 points 10 Ventilation openings 11 Outer cover 12 Rear cabinet 13 Power supply cord support clip 14 Power supply cord EU 15 Power supply cord UK 16 Low trivet 17 High trivet 1 Place the turntable support in the centre of the oven floor so that it can freely rotate around the coupling 2 Place the turntable onto the turntable support Turntable Turntable support system Turntable support Coupl...

Страница 8: ...R WEIGHT POWER knob 4 AUTO COOK button Press to select one of the 2 automatic programmes 5 AUTO COOK PLUS GRILL 1 button Press to select one of the 2 automatic programmes 6 AUTO COOK PLUS GRILL 2 button Press to select one of the 3 automatic programmes 7 AUTO DEFROST button Press to select one of the 5 automatic programmes 8 COOKING MODE button Press to select either microwave grill or dual grill ...

Страница 9: ...POWER knob 4 AUTO COOK button Press to select one of the 2 automatic programmes 5 AUTO COOK PLUS GRILL 1 button Press to select one of the 2 automatic programmes 6 AUTO COOK PLUS GRILL 2 button Press to select one of the 3 automatic programmes 7 AUTO DEFROST button Press to select one of the 5 automatic programmes 8 COOKING MODE button Press to select either microwave grill or dual grill or use to...

Страница 10: ... POWER knob 4 AUTO COOK button Press to select one of the 2 automatic programmes 5 AUTO COOK PLUS GRILL 1 button Press to select one of the 2 automatic programmes 6 AUTO COOK PLUS GRILL 2 button Press to select one of the 3 automatic programmes 7 AUTO DEFROST button Press to select one of the 5 automatic programmes 8 COOKING MODE button Press to select either microwave grill or dual grill or use t...

Страница 11: ... POWER knob 4 AUTO COOK button Press to select one of the 2 automatic programmes 5 AUTO COOK PLUS GRILL 1 button Press to select one of the 2 automatic programmes 6 AUTO COOK PLUS GRILL 2 button Press to select one of the 3 automatic programmes 7 AUTO DEFROST button Press to select one of the 5 automatic programmes 8 COOKING MODE button Press to select either microwave grill or dual grill or use t...

Страница 12: ...POWER knob 4 AUTO COOK button Press to select one of the 2 automatic programmes 5 AUTO COOK PLUS GRILL 1 button Press to select one of the 2 automatic programmes 6 AUTO COOK PLUS GRILL 2 button Press to select one of the 3 automatic programmes 7 AUTO DEFROST button Press to select one of the 5 automatic programmes 8 COOKING MODE button Press to select either microwave grill or dual grill or use to...

Страница 13: ...d 4 When the cooking time is up a single tone is heard and the relays RY1 RY3 RY4 go back to their home position The circuits to the oven lamp power transformer fan motor and turntable motor are cut off 5 When the door is opened during a cook cycle the switches come to the following condition CONDITION SWITCH CONTACT DURING COOKING DOOR OPEN NO COOKING Monitor switch COM NC Open Closed COM NO Clos...

Страница 14: ...r 1 The numbers on the display start the count down to zero 2 The oven lamp cooling fan motor and turntable motor are energized 3 The relay RY2 is energized and the main supply voltage is applied to the top grill heater 4 Now the food is cooked by the top grill heater DUAL COOKING CONDITION MICROWAVE AND GRILL Figure 0 4 on page 37 Enter desired Program cooking time by rotating the TIME WEIGHT kno...

Страница 15: ...arness H V capacitor magnetron or secondary winding of power transformer is shorted 2 If the wire harness or electrical components are short circuited the fuse F2 blows to prevent an electric shock or fire hazard THERMAL CUT OUT 145 C TC01 OVEN The thermal cut out located on the top of the oven cavity is designed to prevent damage to the oven if the foods in the oven catch fire due to over heating...

Страница 16: ... through the air vanes surrounding the magnetron and cools the magnetron This air flows through the oven cavity to remove steam and vapours given off from the heating foods It is then vented through the exhaust air vents at the rear of oven cavity NOISE FILTER The noise filter prevents the radio frequency interference that might flow back in the power circuit ...

Страница 17: ...ED WIRE HARNESS OPENED WIRE HARNESS OVEN LAMP BLOCKED VENTILATION OPENINGS WRONG OPERATION MIS ADJUSTMENT OF SWITCHES HOME FUSE OR BREAKER NO POWER AT WALL OUTLET BLOKED COOLING FAN Home fuse blows when power cord is plugged into wall outlet 88 88 does not operate in display when power cord is plugged into wall outlet Display does not operate properly when STOP button is touched Oven lamp does not...

Страница 18: ... for t second approximately P x t 4 187 calorie is generated On the other hand if the temperature of the water with V ml rises T C during this microwave heating period the calorie of the water is V x T The formula is as follows P x t 4 187 V x T P W 4 187 x V x T t Our condition for water load is as follows Room temperature around 20 C Power supply Voltage Rated voltage Water load 1000 g Initial t...

Страница 19: ...0 x 10 C 900Watts JUDGEMENT The measured output power should be at least 15 of the rated output power CAUTION 1 C CORRESPONDS TO 90 WATTS REPEAT MEASUREMENT IF THE POWER IS INSUFFICIENT B POWER TRANSFORMER TEST WARNING High voltages and large currents are present at the secondary winding and filament winding of the power transformer It is very dangerous to work near this part when the oven is on N...

Страница 20: ...eplaced with high voltage asymmetric rectifier When the asymmetric rectifier is defective check whether magnetron high voltage rectifier high voltage wire or filament winding of the power transformer is shorted CARRY OUT 4R CHECKS NOTE FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER THE BATTERIES OF THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE OF AT LEAST 6 VOLTS BECAUSE OTHERWISE AN INFINITE R...

Страница 21: ...Thermal Cut out Test Parts Name Temperature of ON condition closed circuit C Temperature of OFF condition open circuit C Indication of ohmmeter When room temperature is approx 20 C Thermal cut out 145 C TC01 Below 115 C Above 145 C Closed circuit Thermal cut out 125 C TC02 This is not reset able type Above 125 C Closed circuit If incorrect readings are obtained replace the thermal cut out An open ...

Страница 22: ... Short circuit Between terminal L and RED Short circuit If Incorrect readings are obtained replace the noise filter unit CARRY OUT 4R CHECKS J MOTOR WINDING TEST CARRY OUT 3D CHECKS Disconnect the leads from the motor Using an ohmmeter check the resistance between the two terminals as described in the table below Table Resistance of Motor Motors Resistance Fan motor Approximately 290 Ω Turntable m...

Страница 23: ...ssembly is in four units Control unit Switch Unit LED Unit and Relay Unit Troubleshooting by unit replacement is described according to the symptoms indicated 1 Switch Unit NOTE Check switch unit lead wire harness connection before replacement The following symptoms indicate a defective switch unit Replace the switch unit a When touching the keys a certain key produces no signal at all b When touc...

Страница 24: ...f a specific key does not respond the above method may be used after clearing the control unit to determine if the control unit or switch unit is at fault MC2660E EU UK CH MC2661E EU UK ZM266ST EU UK JMW2061 QN4040 EM2612 SW USAGE 1 Start Quick 2 Not Used 3 Stop 4 Cooking Mode 5 Not Used 6 Auto Defrost 7 Auto Cook plus Grill 2 8 Auto Cook plus Grill 1 9 Auto Cook M RELAY TEST Remove the outer case...

Страница 25: ...ced CARRY OUT 4R CHECKS O PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD PWB IS OPEN To protect the electronic circuits this model is provided with a fine foil pattern added to the input circuit on the PWB this foil pattern acts as a fuse If the foil pattern is open follow the troubleshooting guide given below for repair Problem POWER ON indicator does not light up CARRY ...

Страница 26: ...nizing Signal Circuit The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit It accompanies a very small error because it works on commercial frequency 4 ACL Circuit A circuit to generate a signals which resets the LSI to the initial state when power is supplied 5 Buzzer Circuit The buzzer is responsive to signals from the LSI to emit audi...

Страница 27: ...onnect the power supply cord after the outer case is installed 6 Run the oven and check all functions A On some models the power supply cord between the touch control panel and the oven itself is so short that the two can t be separated For those models check and repair all the controls sensor related ones included of the touch control panel while keeping it connected to the oven B On some models ...

Страница 28: ...itted Please refer to OVEN PARTS CABINET PARTS DOOR PARTS when carrying out any of the following removal procedures BUILT IN FRAME ASSEMBLY REMOVAL To remove the built in frame assembly proceed as follows 1 Remove the four screws securing the frame assembly to the oven cavity two from the top and two from the hinge side 2 Remove the two screws securing the frame assembly to the control panel frame...

Страница 29: ...r to base plate 6 Remove the transformer from the base plate by sliding it away from the oven cavity and lifting it 7 Now the power transformer is free MAGNETRON REMOVAL 6 Remove the magnetron from the waveguide with care so the magnetron antenna is not hit by any metal object around the antenna 1 CARRY OUT 3D CHECKS 2 Disconnect the H V wire B and filament lead of the transformer from the magnetr...

Страница 30: ...lade will be free CAUTION Do not reuse the removed fan blade as the fixing hole may be oversize 13 Remove the two 2 screws holding the fan motor to the fan duct 14 Now the fan motor is free INSTALLATION 1 Install the fan motor to the fan duct with the two 2 screws 2 Install the fan blade to the fan motor shaft according to the following procedure 1 Hold the centre of the bracket which supports sha...

Страница 31: ...y with one 1 screw and ensure that this screw is tight 3 Connect the brown and blue wire leads of power supply cord to the noise filter correctly referring to the Pictorial Diagram C 4 a Figure C 4 a Replacement of Power Supply Cord Figure C 4 b Installation of Power Supply Cord GRILL HEATING ELEMENT REMOVAL 1 CARRY OUT 3D CHECKS 2 Remove the one 1 screw holding the exhaust duct to the oven cavity...

Страница 32: ...where the monitor switch has activated with the door closed The vertical position of the latch hook should be placed where the monitored latch switch and stop switch have activated with the door closed 4 Secure the screws firmly 5 Make sure of the monitored latch switch stop switch and monitored switch operation If those switches have not activated with the door closed repeat step 1 4 After adjust...

Страница 33: ...o 2 hole of upper and lower oven hinges 5 Re install choke cover to door panel by pushing Note After any service to the door A Make sure that monitored latch switch stop switch and monitor switch are operating properly Refer to chapter Test Procedures Switch Test page 21 B An approved microwave survey meter should be used to assure compliance with proper microwave radiation emission limitation sta...

Страница 34: ...uments that comply with the requirement for instrumentations as prescribed by the performance standard for microwave ovens must be used for testing Recommended instruments are NARDA 8100 NARDA 8200 HOLADAY HI 1500 SIMPSON 380M 2 Place the oven tray into the oven cavity 3 Place the load of 275 15 ml of water initially at 20 5 C in the centre of the oven tray The water container should be a low form...

Страница 35: ...Disconnect the supply 2 Door opened and wedge open 3 Discharge the high voltage capacitor RE WIRING Ensure the following 1 Wires must not touch a High voltage parts Magnetron high voltage transformer high voltage capacitor and high voltage rectifier b Parts that become hot Heating elements oven lamp oven cavity magnetron and high voltage transformer c Sharp edges Bottom plates oven cavity waveguid...

Страница 36: ...IL OVEN THERMAL CUT OUT SWITCH STOP CONTROL UNIT FAN MOTOR OVEN LAMP TURNTEBLE MOTOR HEATING CAPACITOR H V RECTIFIER MONITORED SWITCH LATCH MONITOR SWITCH ASYMMETRIC RECTIFIER LIVE EARTH FUSE MAGNETRON THERMAL CUT OUT NOISE FILTER UNIT F1 FUSE LIVE NOISE SOPPRESSION COIL OVEN THERMAL CUT OUT SWITCH STOP CONTROL UNIT FAN MOTOR OVEN LAMP TURNTEBLE MOTOR HEATING CAPACITOR H V RECTIFIER MONITORED SWIT...

Страница 37: ...ESSION COIL OVEN THERMAL CUT OUT SWITCH STOP CONTROL UNIT FAN MOTOR OVEN LAMP TURNTEBLE MOTOR HEATING CAPACITOR H V RECTIFIER MONITORED SWITCH LATCH MONITOR SWITCH ASYMMETRIC RECTIFIER EARTH FUSE MAGNETRON THERMAL CUT OUT NOISE FILTER UNIT F1 FUSE NOISE SOPPRESSION COIL OVEN THERMAL CUT OUT SWITCH STOP CONTROL UNIT FAN MOTOR OVEN LAMP TURNTEBLE MOTOR HEATING CAPACITOR H V RECTIFIER MONITORED SWITC...

Страница 38: ...m TURNTEBLE MOTOR POWER TRANSFORMER LATCH SWITCH H V CAPACITOR H V RECTIFIER SHORT PROTECTOR HIGHT VOLTAGE COMPONENTS MAGNETRON FAN MOTOR MAINS SUPPLY CORD NOISE FILTER UNIT OVEN LAMP TOP HEATER MAGNETRON THERMAL CUT OUT STOP SWITCH MONITOR SWITCH OVEN THERMAL CUT OUT Switch PWB ...

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