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       Section 

1 Basic Information      

1-1

Safe Servicing Practices

Avoid personal injury and/or property damage by observing important Safe Servicing Practices.  

Following are some limited examples of safe practices:

1.   DO NOT attempt a product repair if you have any doubts as to your ability to complete the repair in a safe and  

satisfactory manner.

2.   Always Use The Correct Replacement Parts as indicated in the parts documentation.  Substitutions may defeat  

compliance with Safety Standards Set For Home Appliances.  Do not exceed maximum recommended wattage on  
light bulb replacements.  Doing so could blow fuses and/or damage transformers.  

3.   Before servicing or moving an appliance:
 

•   Remove power cord from the electrical outlet, trip circuit breaker to the OFF position, or remove fuse.

4.   Never interfere with the proper operation of any safety device.  

5.   Use ONLY REPLACEMENT PARTS CATALOGED FOR THIS APPLIANCE.  Substitutions may defeat compliance with  

Safety Standards Set For Home Appliances. 

6.   GROUNDING: The standard color coding for safety ground wires is GREEN, or GREEN with YELLOW STRIPES.  

Ground leads are not to be used as current carrying conductors.  It is EXTREMELY important that the service  
technician reestablish all safety grounds prior to completion of service.  Failure to do so will create a hazard.

7.   Prior to returning the product to service, ensure that:
 

•   All electrical connections are correct and secure.

 

•   All electrical leads are properly dressed and secured away from sharp edges, high-temperature components,  
 

and moving parts.

 

•   All non-insulated electrical terminals, connectors, heaters, etc. are adequately spaced away from all metal  
 

parts and panels.

 

•   All safety grounds (both internal and external) are correctly and securely connected.

 

•   All panels are properly and securely reassembled.

Summary of Contents for HMV5053C

Page 1: ... to the complexity and the risk of high voltage electrical shock Bosch does not recommend that customers service their own units This material is intended for the sole use of BSH authorized persons and may contain confidential and proprietary information Any unauthorized review use copying disclosure or distribution in any format is prohibited ...

Page 2: ...e with the proper operation of any safety device 5 Use ONLY REPLACEMENT PARTS CATALOGED FOR THIS APPLIANCE Substitutions may defeat compliance with Safety Standards Set For Home Appliances 6 GROUNDING The standard color coding for safety ground wires is GREEN or GREEN with YELLOW STRIPES Ground leads are not to be used as current carrying conductors It is EXTREMELY important that the service techn...

Page 3: ... Cut Out Hood 2 5 Turntable Motor 2 5 Cooling Fan Motor 2 5 Hood Fan Motor 2 5 Hood Lamp 2 5 Section 3 Troubleshooting and Testing Warnings and Cautions 3 1 Troubleshooting Guide Chart 3 2 Test Procedures 3 3 Section 4 Component Teardown Warnings and Cautions 4 1 Hood Exhaust Louver Removal 4 2 Removal Of Oven From Wall 4 2 Outer Case Removal 4 3 Power Transformer Removal 4 3 High Voltage Rectifi ...

Page 4: ... This service manual is intended for use by persons having electrical and mechanical training and a level of knowledge of these subjects generally considered acceptable in the appliance repair trade BSH Home Appliances cannot be responsible nor assume any liability for injury or damage of any kind arising from the use of this manual WARNING Never operate the oven until the following points are ens...

Page 5: ...the outer case cabinet removed because a microwave oven generates high voltage in the circuit If you intend to operate the oven employing the high frequency switching power converter circuit you should take special precautions to avoid an electrical shock hazard The high voltage transformer high voltage capacitor and high voltage diode have energized high voltage potential of approximately 4KV The...

Page 6: ...case is installed 7 Run the oven and check all functions After repairing 1 Reconnect all leads removed from components during testing 2 Reinstall the outer case cabinet 3 Reconnect the power supply cord after the outer case is installed 4 Run the oven and 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 wat...

Page 7: ... The water container shall be a low form of 600 ml 20 oz beaker with an inside diameter of approx 8 5 cm 3 1 2 in and made of an electrically nonconductive material such as glass or plastic The placing of this standard load in the oven is important not only to protect the oven but also to insure that any leakage is measured accurately 4 Set the cooking control on Full Power Cooking Mode 5 Close th...

Page 8: ...oad in the oven is important not only to protect the oven but also to insure that any leakage is measured accurately 4 Set the cooking control on Full Power Cooking Mode 5 Close the door and select a cook cycle of several minutes If the water begins to boil before the survey is completed replace it with 275 ml of cool water C Leakage test with enclosure installed 1 Grasp probe of survey instrument...

Page 9: ...wer P 80 approx 80 of Full Power P 70 approx 70 of Full Power P 60 approx 60 of Full Power P 50 approx 50 of Full Power P 40 approx 40 of Full Power P 30 approx 30 of Full Power P 20 approx 20 of Full Power P 10 approx 10 of Full Power Oven Cavity Light Safety Standard UL Listed FCC Authorized DHHS Rules CFR Title 21 Chapter 1 Subchapter J Canadian Standards Association Health CANADA Industry Cana...

Page 10: ...rd and plug must be connected to a separate 120 Volt AC 60 Hz 15 Amp or more dedicated line using a grounded receptacle When installing this appliance observe all applicable codes and ordinances A short power supply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord Where a two pronged wall receptacle is encountered it is the personal responsibility and obliga...

Page 11: ...The rollers on WKH VXSSRUW VKRXOG oW inside the turntable bottom ridge See Caring for the Filters section glass Section 1 Basic Information 1 10 Oven Diagram Located on back of Control Panel The microwave oven is designed to make your cooking experience as enjoyable and productive as possible To get you up and running quickly the following is a list of the oven s basic features 1 Metal Shielded Wi...

Page 12: ...oven will revert to the OFF condition 6 When the door is opened during a cook cycle monitor switch door sensing switch primary interlock switch and secondary interlock relay are activated with the following results The circuits to the stirrer motor the cooling fan motor the turn table motor and the high voltage components are de energized and the digital read out displays the time still remaining ...

Page 13: ...then discharged vertically at rear center top of the oven into the customer s vent system 2 Horizontal Venting The air handing is the same as Vertical Venting except that f nal air discharge is directed horizontally out from the top rear of oven into the customer s vent system 3 Re circulation Inside venting The air handing is the same as VERTICAL VENTING except that the final air discharge is dir...

Page 14: ...Section 2 Operation 2 3 For HMV505 U ...

Page 15: ...Section 2 Operation 2 4 For HMV505 C ...

Page 16: ...uit To drive the magnetron fan motor turntable motor hood motor and light the oven lamp and hood lamp 8 Indicator Circuit This circuit consists of 25 segments and 4 common electrodes using a Light Crystal Display 9 Back Light Circuit A circuit to drive the back light Light emitting diodes LD1 LD4 DOOR OPEN MECHANISM The door is opened by pulling the door handle refer to the Figure 2 3 DOOR SENSING...

Page 17: ...ing switch secondary interlock relay RY2 relay RY1 primary interlock switch and monitor switch for proper operation Refer to Test Procedure CAUTION Monitor fuse and switch are replaced as an assembly NOTE THERMAL CUT OUT HOOD This thermal cut out located on the right base plate It is designed to automatically turn on the hood fan motor whenever the hot air rising from the conventional range below ...

Page 18: ...ed screwdriver 4 Disconnect the leads to the primary of the power transformer 5 Ensure that the leads remain isolated from other components and oven chassis by using insulation tape WARNING When the testing is completed 1 Disconnect the power supply cord 2 Open the door and block it open 3 To discharge high voltage capacitor wait for 60 seconds and then short circuit the connection of the high vol...

Page 19: ...Section 3 Troubleshooting and Testing 3 2 HUMIDITY SENSOR 8 6 7 10 ...

Page 20: ...easuring cup with 16 oz 453 cc of tap water and measure the temperature of the water with a thermometer or thermocouple temperature tester Stir the thermometer or thermocouple through the water until the temperature stabilizes Record the temperature of the water 2 Place the cup of water in the oven Operate oven at 100 POWER selecting more than 60 seconds cook time Allow the water to heat for 60 se...

Page 21: ...ect the power supply cord and then remove outer case 2 Open the door and block it open 3 Discharge high voltage capacitor See Warnings and Instructions on page 3 1 4 Isolate the rectifier from the circuit Using the highest ohm scale of the meter read the resistance across the terminals and observe reverse the leads to the rectifier terminals and observe meter reading If a short is indicated in bot...

Page 22: ...should indicate a closed circuit unless the temperature of the thermal cut out reaches approximately 230 F 110 C An open thermal cut out indicates overheating of the oven exchange thermal cut out and check inside of oven cavity for improper setting of cooking time or operation of control unit Check for restricted air flow through the vent holes of the oven cavity especially the cooling fan and air...

Page 23: ...e common COM and normally open NO terminal of the switch The meter should indicate an open circuit with the door open and a closed circuit with the door closed If improper operation is indicated replace the door sensing switch 5 Reconnect all leads removed from components during testing 6 Reinstall the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the...

Page 24: ...is indicated the switch may be defective After testing the monitor switch reconnect wire lead to monitor switch COM terminal and check continuity of monitor circuit 5 Reconnect all leads removed from components during testing 6 Reinstall the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all functions HOOD THERMAL CUT OUT TEST 1 Disc...

Page 25: ... The touch control panel consists of circuits including semiconductors such as Logic Unit ICs etc Therefore unlike conventional microwave ovens proper maintenance cannot be performed with only a voltmeter and ohmmeter In this service manual the touch control panel assembly is divided into two units Control Unit and Key Unit and troubleshooting by unit replacement is described according to the symp...

Page 26: ...TROL UNIT The following symptoms indicate a defective control unit Before replacing the control unit perform the Key unit test Procedure M to determine if control unit is faulty 1 In connection with pads a When touching the pads a certain group of pads do not produce a signal b When touching the pads no pads produce a signal 2 In connection with indicators a At a certain digit all or some segments...

Page 27: ...h is closed either close the door or short the door sensing switch connector Use the Key unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the CANCEL pad making momentary contact If the control unit responds by clearing with a beep the key unit is faulty and must be replaced If the control unit does not respond it is faulty and must be...

Page 28: ...or oven cavity are not intact 3 If the door is not closed 4 If the outer case cabinet is not fitted WARNING Disconnect oven from power supply before removing outer case Discharge high voltage capacitor before touching any oven components or wiring after removing outer case CAUTION To prevent an electric shock take the following precautions 1 Before wiring A Disconnect the power supply B Open the d...

Page 29: ...ort from the oven cavity 4 Remove the three 3 screws holding the oven outer case cabinet to the top cabinet 5 While supporting the front of the oven and release the oven from the unit mounting plate 6 Pull the power cord out of the wall cabinet and remove the oven 7 The oven is now free and can be placed on the work surface selected for servicing the oven 8 Installation is the reverse of this proc...

Page 30: ... wire harness from transformer 6 Disconnect high voltage wire from the transformer 7 Disconnect filament leads of transformer from the magnetron and capacitor 8 Remove four 4 screws holding the transformer to bottom plate RE INSTALL 1 Install by sliding the transformer on the bottom plate with its primary terminals toward the control panel 2 Secure the transformer with four 4 screws to bottom plat...

Page 31: ...open 3 Discharge high voltage capacitor 4 Disconnect the high voltage wire lead of the high voltage diode assembly from the magnetron 5 Disconnect the filament lead of the transformer from the magnetron 6 Carefully remove three 3 mounting screws holding the magnetron to waveguide When removing the screws hold magnetron to prevent it from falling 7 Remove the magnetron from the unit with care so th...

Page 32: ...guide 8 Remove the fan motor from the fan guide and the fan blade by pulling the fan motor with your hand The fan blade will fall as the motor is removed INSTALLATION 1 Pick up the fan blade with one hand and insert the fan motor shaft into the fan blade hole with the other hand 2 Install fan motor to fan guide with two 2 screws 3 Re install the fan guide to the back wind guide with 4 Reconnect th...

Page 33: ...nel is available either from the power line of the oven itself or from an external power source 4 Disconnect the leads to the primary of the power transformer 5 Ensure that these leads remain isolated from other components and oven chassis by using insulation tape 6 After that procedure re connect the power supply cord After checking performance of the touch control panel 1 Disconnect the power su...

Page 34: ...ove one 1 screw holding turntable motor to the oven cavity 8 The turntable motor is now free HOOD LAMP SOCKET 9 Disconnect the wire leads from the lamp socket 10 Remove the two lamp covers and remove the two 2 screws holding the lamp socket to the base plate Remove the lamps The lamp socket is now free Oven Lamp And Lamp Socket Removal 1 Disconnect the power supply cord remove the hood exhaust lou...

Page 35: ...PCB to the control panel 13 The PCB is now free To discharge the high voltage capacitor wait for 60 seconds and then short circuit the connection of the high voltage capacitor that is the connecting lead of the high voltage diode against the chassis with the use of an insulated screwdriver NOTE Stirrer Motor Removal 1 Disconnect the power supply cord remove oven from wall then remove outer case 2 ...

Page 36: ...ve the control assembly referring to the the procedure of Control Assembly And Power PCB Removal If door sensing switch primary interlock switch and monitor switch do not operate properly due to a misadjustment the following adjustment should be made 5 Loosen the two 2 screws holding latch hook to the oven cavity front flange 6 With door closed adjust latch hook by moving it back and forth and up ...

Page 37: ...ure of Hood Exhaust Louver Removal 6 Disconnect wire lead from the top left corner of cavity 7 Lift up the door assembly to release the upper and lower door hinge pins from the upper and lower oven hinges Door assembly is now free DOOR ASSEMBLY RE INSTALL 1 On re installing door insert the lower oven hinge to lower door hinge pin 2 Insert the upper oven hinge to upper door hinge pin 3 Shut the doo...

Page 38: ... seal preventing leakage of microwave energy from oven cavity during cook cycle This function does not require that door be air tight moisture tight or light tight Therefore occasional appearance of moisture light or sensing of gentle warm air movement around oven door is not abnormal and does not indicate a leakage of microwave energy from oven cavity NOTE Door Disassembly 1 Disconnect the power ...

Page 39: ...nel and remove it from cavity and hold it at the front plate by the control panel flange 6 Disconnect the wire leads from the control panel 7 Remove the one 1 screw holding the hood motor to cavity and remove the hood motor 8 Remove there 3 screws from the air duct to cavity To discharge the high voltage capacitor wait for 60 seconds and then short circuit the connection of the high voltage capaci...

Page 40: ...om portal 583000001195114 ARA EN C JUNE 2016 Copyright by BSH Home Appliances Corporation 1901 Main Street Suite 600 Irvine CA 92614 800 444 9091 This material is intended for the sole use of BSH authorized persons and may contain confidential and proprietary information Any unauthorized review use copying disclosure or distribution in any format is prohibited ...

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