Bosch HMB406 Service Manual

Microwave OvenHMB402HMB405HMB406R080015E, Edition 1, Rev. 1 APRIL 2004B/S/H/ assumes no responsibility for any repairs made on our products by anyone

CIRCUIT DESCRIPTIONGENERAL DETAILS• The low voltage transformer supplies the necessaryvoltage to the micom controller when power cord isplugged in.• W

CAUTIONS• Be sure to check microwave leakage prior toservicing the oven if the oven is operative prior toservicing.• The service personnel should info

MEASUREMENT WITH OUTER CASEREMOVED• When you replace the magnetron, measure formicrowave energy leakage before the outer case isinstalled and after al

• Microwave power output measurement is made withthe microwave oven supplied at its rated voltage andoperated at its maximum microwave power setting w

D. PCB ASSEMBLY REMOVAL1) Remove the control panel assembly from thecavity. (Refer to control panel assembly removalon previous page.)2) Remove screws

F. AIR DUCT ASSEMBLY REMOVAL1) Disconnect the leadwire from lamp and MGT thermostat.2) Removethe mounting screw to the magnetron.G. MAGNETRON REMOVAL1

K. REMOVING THE TURNTABLE MOTOR1) Remove the glass turntable.2) Remove the rotating ring ass’y by hand.3) Remove the turntable motor cover.The turntab

A. PRIMARY INTERLOCK SWITCH TESTWhen the door release button is depressed slowlywith the door closed, an audible click should beheard at the same time

5-8CAUTIONS1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THEOUTER CASE FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHAR

5-9COMPONENTS TEST PROCEDURE RESULTSHIGH VOLTAGECAPACITORHIGH VOLTAGEDIODENOTE :Some inexpensive metersmay indicate infiniteresistance in both directi

This device is to be serviced only by properly qualified service personnel.Consult the service manual for proper service procedures to assure continue

5-10COMPONENTS TEST PROCEDURE RESULTSRELAY 2FAN MOTOR(Wire leads removed)TURNTABLEMOTOR(Wire leads removed)Check for continuity of relay 2 with anohm-

TROUBLE SHOOTINGWHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER, EVALUATE THE COMPLAINT CAREFULLY. IFTHE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUS

1. Incomplete segments.• Segment missing.• Partial segment missing.• Digit flickering (NOTE: Slight flickering is normal.)2. Colon does not turn on or

5-13CONDITION CHECK RESULT CAUSE REMEDY1. Fuse blows. Continuity.No continuity.Continuity.Shorted contact atthe primary switch.Replace fuse,primary, m

5-14CONDITION CHECK RESULT CAUSE REMEDY1. Setting timedoes not countdown whentouching STARTpad.2. Fan motor oroven lamp donot turn on.No continuity.Co

5-15CONDITION CHECK RESULT CAUSE REMEDYNo microwaveoscillation.No continuity.Continuity.AbnormalDefective highvoltagetransformer.Replace highvoltagetr

KBGRWPKBlackBlueYGYellow-GreenGreenRedWhitePinkKKKKKKKKPKWWWWWWWWWRRRGGGYGBBBRFor ModelHMB402HMB405HMB4066-1

6-2THIS IS THE LAST PAGE OF THIS MANUAL

(Page)SAFETY PRECAUTIONS ---------------------------------------------------------------------Inside front coverSPECIFICATIONS -----------------------

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1-1SPECIFICATIONSMODEL NO. HMB402, HMB405, HMB406Rated Power Consumption 1,500 WOutput 1100 W (*IEC60705 Rating standard)Frequency 2,450 MHzPower Supp

• DO NOT operate on a 2-wire extension cord duringrepair and use.• NEVER TOUCH any oven components or wiring duringoperation.• BEFORE TOUCHING any par

3-1INSTALLATIONSINSTALLING1. Empty the microwave oven and clean inside it witha soft, damp cloth. Check for damage such asmisaligned door, damage arou

FEATURESCONTROL PANEL1. DISPLAY: Displays the timer, the time of day, cooking time,power level being used and cooking functions selected.2. PERSONAL C

SCHEMATIC DIAGRAM4-2IMPORTANT SAFETY NOTE: THE SHADED AREAS ON THIS SCHEMATIC DIAGRAM INCORPORATE SPECIAL FEATURES IMPORTANT FOR PROTECTI