Goldstar MA-2005ST manual

MICROW A VE OVEN SER VICE MANUAL MODEL : MA-2005ST CAUTION BEFORE SERVICING THE UNIT , READ THE SAFETY PRECAUTIONS IN THIS MANUAL. http://www.LGEservice.com E-mail:Techsupport@LGEservice.com[...]

This device is to be serviced only by properly qualified service personnel. Consult the service manual for proper service procedures to assure continued safety operation and for precautions to be taken to avoid possible exposure to excessive microwave energy. PRECAUTIONS T O BE OBSER VED BEFORE AND DURING SER VICING TO A V OID POSSIBLE EXPOSURE T O[...]

- 8 - 1. How a Microwave Oven W orks The microwave oven is one of the great inventions of the 20th century - millions of homes in world have one. Microwave ovens are popular because they cook food incredibly quickly . They are also extremely efficient in their use of electricity because a microwave oven heats only the food - nothing else. A microwa[...]

- 9 - 2-1. Function & T ype (2/2) 2) GRILL COOKING This is a method of cooking with radiant heat from the grill heater on the top of the oven. This is a traditional way of cooking which quickly seals and browns food evenly . The temperature inside the oven is fixed at 180°C, which is ideal grilling temperature for this oven. 3) CONVECTION COOK[...]

- 10 - 1. Installation 1. Unpack your oven and place it on a flat level surface. 2. Place your oven in the level location of tour choice with more than 85cm height but make sure there is at least 30cm of space on the top and 10cm at the rear for proper ventilation. The front of the oven should be at least 8cm from edge of the surface to prevent tip[...]

- 11 - 2.COOKING UTENSILS Utensils should be checked to ensure that they are suitable for use in the microwave oven. The following chart summaries the proper use of cooking utensils in your oven: Microwave 1. Most glass, glass ceramic, and heat resistant glassware utensils are excellent. Those with metal trim should not be used in a microwave oven.[...]

- 12 - 1. History of dielectric heating In 1945, Dr . Spencer working for RA YTHEON Co. in the U.S.A found out a pieces of chocolate in his pocket melting suddenly by th e electric wave (ultra high frequency wave using for radar) on his experiment for radar . then began research in heating matters b y the electric wave. So far , experiments for hea[...]

- 13 - 3. The safety of microwave oven Since the microwave oven can’t make the native fire like gas, you have no use for worrying about the fire. Because it doesn’t become hot like the ordinary electric range. It has been used in the dinner car of the trains etc. Microwave oven has the shielded structure strictly with metal case not to leak ele[...]

- 14 - 3-2. Conventional heating vs. dielectric heating 1. Conventional heating * The heat energy from the sources of the heating power shall be transmitted from the warm surface to the cold inside. * Heating with the strong fire: The surface of the food shall be well done, but be burnt to have a black side, and the center of the food shall not be [...]

- 15 - 4-1. Construction of microwave oven DOOR PARTS LATCH BOARD PARTS CONTROL PANEL PARTS INTERIOR PARTS BASE PLATE PARTS OVEN CAVITY PARTS Magnetron Inject microwave to oven. Cavity Cabinet locking in microwave and holding food. Door Gate coming in and out food. It has window and seal structure Controller Control and supervise operating state of[...]

- 16 - After plugging your oven into a standard household socket, press start button or turn the timer . And then switches (primary , secondary , timer) close the circuit. Eventually the input power will be applied to turntable motor , timer motor , fan motor , oven lamp and high voltage transformer . A high voltage of 2,100 volts AC is generated i[...]

- 17 - 4-3. W ARNING - High voltage circuit ( 4,000 volt ) * The half-wave voltage doubler circuit consists of the secondary winding of the high voltage transformer , H.V . diode (rectifier), and H.V . capacitor . The H.V . diode allows alternating current (AC) to flow in one direction only and rectifies it to pulsating direct current (DC). The H.V[...]

- 18 - * The magnetron is the energy source for the microwave oven. The magnetron is a vacuum tube of special construction. It is basically a diode with addition of a magnetic field. It consists of a small, coiled heating element (filament) made of tungsten which readily emits electrons when heated. This element serves as the cathode (negative elem[...]

- 19 - 4-4. Microwave generation system_Magnetron (2/2) * In order to create an electron flow from cathode to anode, the cathode must be heated and a potential difference must exist between the two. This is accomplished by heating the cathode with 3, 4 to 3,5 V AC. ( from the filament winding of the high voltage transformer) and applying a negative[...]

- 20 - What is Multi-W ave • The multi-W ave system heats food more evenly than convectional microwave ovens. 5-1. Multiwave system[...]

- 21 - What’ s the infrared sensor? Y ou may be annoyed when you defrost or reheat food with microwave oven. If you reheat soup, the result is superficial. The surface is hot but inside of the soup is still cold. Y ou have to set the clock and push “Start” again. The cooking time is much longer than you expected. LG microwave oven reduce cook[...]

- 22 - What’ s does move automatically? Conventional microwave oven with grill has a heater on the ceiling of cooking room. Whether you cook a pizza or chicken, the position of heater is unmovable. We changed the old way . LG heater is moving when you choose grill, the heater goes down. The angle of heater varies as to each menu. Y ou don’t hav[...]

1-1 This microwave oven is designed for household use only. It is not recommended for commercial purposes. ITEM MODEL Power Requirement Power Output Microwave Frequency Magnetron Timer Outside Dimensions Cavity Dimensions Net Weight Shipping weight Control Complement Nameplate Location Accessories DESCRIPTION MA-2005ST 120 Volts AC 60 Hz 1,550 Watt[...]

FEA TURES CONTROL P ANEL 1. DISPLAY WINDOW. 2. ONE TOUCH CONTROL: This menu has been pre programmed to cook food automatically by one touch. 3. AUTO DEFROST: This feature provides you with the best defrosting method for frozen foods. 4. CUSTOM COOK: This feature allows you to set and execute a frequently used single stage program. 5. NUMBER: These [...]

4-2 OPERA TING SEQUENCE The following is a description of component functions during oven operation. 1. SETTING THE CLOCK ex.) To set 4:30, touch number key [4],[3], and [0]. NOTE: 1) This is a 12 hour clock. 2) Clock will operate as long as power is applied to the oven. 2. CANCEL FUNCTION Touch the pad whenever you need to cancel an entry or a fun[...]

SCHEMA TIC DIAGRAM 4-3 RD RD BK PRIMARY  SWITCH WH WH WH WH YL MAGNETRON RD  H.V. CAPACITOR H.V. DIODE FUSE 20A AC 120V 60Hz BL L N MICOM  CONTROLLER F.M. TRANSFORMER H.V. ** NOTE : DOOR IS OPENED. BK : BLACK BL : BLUE YL : YELLOW RD : RED WH : WHITE PK : PINK GN : GREEN BN : BROWN T.T.M. O.L. CN1 PT1 1 2 3 4 5 6 7 8 BK BK GN G[...]

CIRCUIT DESCRIPTION GENERAL DET AILS ¥ The low voltage transformer supplies the necessary voltage to the micom controller when power cord is plugged in. ¥ When the door is closed, the primary switch is ON, the secondary switch is ON, and the monitor switch opens (contact COM and NO). WHEN SELECTING COOKING POWER LEVEL AND TIME ¥ The micom contro[...]

CAUTIONS ¥ Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to servicing. ¥ The service personnel should inform the manufacture importer, or assembler of any certified oven unit found to have a microwave emission level in excess of 5 mW/cm 2 and should repair any unit found to have excessive emission l[...]

MEASUREMENT WITH OUTER CASE REMOVED ¥ When you replace the magnetron, measure for microwave energy leakage before the outer case is installed and after all necessary components are replaced or adjusted. Special care should be taken in measuring the following parts. (Circled area of Fig. below) - Around the magnetron - The waveguide MEASUREMENT WIT[...]

¥ Microwave power output measurement is made with the microwave oven supplied at its rated voltage and operated at its maximum microwave power setting with a load of (1000±5) g of potable water. ¥ The water is contained in a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately[...]

D. PCB ASSEMBL Y REMOV AL 1) Remove the control panel assembly from the cavity. (Refer to control panel assembly removal on previous page.) 2) Remove screws which hold the PCB SUB ASSÕY to the control panel. 3) Disconnect the flat cable from the PCB SUB ASSÕY and take off the PCB SUB ASSÕY E. DOOR MAIN ASSEMBL Y REMOV AL 1) Open the door. 2) Rem[...]

5-5 F . AIR DUCT ASSEMBL Y REMOV AL 1) Disconnect the leadwire from the lamp. 2) Remove the mounting screw to the magnetron. G. MAGNETRON REMOV AL 1) Disconnect the leadwire from the magnetron. 2) Carefully remove the mounting screws holding the magnetron and the waveguide. 3) Remove the magnetron ASSÕY until the tube is clear from the waveguide. [...]

I. HIGH VOL T AGE TRANSFORMER REMOV AL 1) Discharge the high voltage capacitor. 2) Disconnect the leadwire from magnetron, high voltage transformer, and capacitor. 3) Remove the screw holding the high voltage transformer to the baseplate. J. F AN MOTOR ASSEMBL Y REMOV AL 1) Discharge the high voltage capacitor. 2) Disconnect the leadwire from fan m[...]

A. PRIMARY INTERLOCK SWITCH TEST When the door release button is depressed slowly with the door closed, an audible click should be heard at the same time or successively at intervals. When the button is released slowly, the latches should activate the switches with an audible click . If the latches do not activate the switches when the door is clos[...]

5-8 CAUTIONS 1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE OUTER CASE FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER. (SEE PAGE 2-1) 2. ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WIT[...]

5-9 COMPONENTS TEST PROCEDURE RESUL TS HIGH VOLTAGE CAPACITOR HIGH VOLTAGE DIODE NOTE : Some inexpensive meters may indicate infinite resistance in both direction. Measure the resistance. (Ohm-meter scale: Rx1000) ¥ Terminal to terminal. Measure the resistance. (Ohm-meter scale: Rx1000) ¥ Terminal to case. Measure the continuity (Forward). (Ohm-m[...]

5-10 COMPONENTS TEST PROCEDURE RESUL TS RELAY 2 FAN MOTOR (Wire leads removed) TURNTABLE MOTOR (Wire leads removed) Check for continuity of relay 2 with an ohm-meter. (Remove wire leads from relay 2 and operate the unit.) Measure the resistance. (Ohm-meter scale: R x 1) Measure the resistance. (Ohm-meter scale: R x 1 ) POWER LEVEL 1 4 sec 18 sec 2 [...]

TROUBLE SHOOTING WHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER, EVALUATE THE COMPLAINT CAREFULLY. IF THE FOLLOWING SYMPTOMS APPLY, PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE MICROWAVE OVEN. THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL. 5-1 1 CAUTIONS 1. Check grounding before checking for trouble. 2. Be careful of the high voltage circui[...]

1. Incomplete segments. ¥ Segment missing. ¥ Partial segment missing. ¥ Digit flickering (NOTE: Slight flickering is normal.) 2. Colon does not turn on or blink. 3. A distinct change in the brightness of one or more numbers in display. 4. One or more digits in the display are not lighting. 5. Display indicates a number different from one touched[...]

5-13 CONDITION CHECK RESUL T CAUSE REMEDY 1. Fuse blows. Continuity. No continuity. Continuity. Shorted contact at the primary switch. Replace fuse, primary, monitor, secondary switches, and RELAY(RY2) of P.C.B Assembly. No continuity. Normal. Defective high voltage capacitor. Replace high voltage capacitor. Fuse blows again Defective high volt- ag[...]

5-14 CONDITION CHECK RESUL T CAUSE REMEDY 1. Setting time does not count down when touching START pad. 2. Fan motor or oven lamp do not turn on. No continuity. Continuity. Continuity Defective PCB assembly. Loose connection. Replace PCB assembly. Connect them tightly. No continuity Abnormal Check fan motor. Defective fan motor. Replace fan motor. A[...]

5-15 CONDITION CHECK RESUL T CAUSE REMEDY No microwave oscillation. No continuity. Continuity. Abnormal Defective high voltage transformer. Replace high voltage transformer. Normal Defective PCB assembly. Replace PCB assembly. Disconnect the wire leads from relay 2 and check continuity of relay 2. (Operate the unit) Check high vol- tage transformer[...]

DOOR PARTS LATCH BOARD PARTS CONTROL PANEL PARTS INTERIOR PARTS BASE PLATE PARTS OVEN CAVITY PARTS 6-1 EXPLODED VIEW INTRODUCTION[...]

6-2 13552A 13213A 13581A 13720D 14970A 14026A 13536A 13352A DOOR P ARTS[...]

6-3 26638A 23572A 23550 D 268711 24781M WTP 01 8 WTT028 24510L 2 50201 24970A CONTROLLER P ARTS[...]

6-4 948503 340511 33052M 36549S 34036 W 33390G 35889A WTP 013 WTT 020 WSZ185 33112U OVEN CA VITY P ARTS[...]

6-5 43501A 43500A 466001 WSZ085 4660 01 466003 LA TCH BOARD P ARTS[...]

6-6 568771 56930V 56411A 54974S 55006F 50 FZZA WSZ002 WTT028 WSZ085 WSZ002 56549F WTT037 WSZ002 WTT028 WSZ002 55900A 56851D 54810C 55262A 56912B 50CZZH 56324A WSZ002 WSZ002 34930W 948502 INTERIOR P ARTS[...]

6-7 63302L 63303L 63303R 948501 63302R 56170D WSZ002 WTT021 WTT021 65006B 65006B BASE PLA TE P ARTS[...]

8-1 SCHEMA TIC DIAGRAM OF P .C.B. 7-2 55900A 2B72125A FAN R 56170D 6170W1D012A TRANSFORMER,HIGH VOLTAGE R 56324A 2B73104A MAGNETRON R 56324A 2B73104B MAGNETRON * 56411A 6411W2A002V POWER CORD ASSY R 56549F 6549W1F001E MOTOR(CIRC),FAN R 56851D 6021W3B001A CABLE ASSY,DIODE R 568771 6877W1A187A LEAD WIRE ASSY R 56912B 6912W3B002G LAMP[OVEN/BASELESS] R[...]

9-1 P .C.B. P AR TS LIST 8-2 PRINTED CIRCUIT BOARD R : SERVICE PARTS * : ALTERNATE PARTS N : NOT SERVICE PARTS BZ1 6908W3YA01A BUZZER,PIEZO CERAMIC GPB-B-26B2.1ES(EXTERNAL) R C02 0CE2272H638 CAPACITOR,AL.ELECTROLYTIC 220UF SME 25V M FM5 TP5 R C03 0CE2272H638 CAPACITOR,AL.ELECTROLYTIC 220UF SME 25V M FM5 TP5 R C07 0CE4751K638 CAPACITOR,AL.ELECTROLYT[...]