Page 3
The manufacturer and seller are not to be held responsible for any liability incurred from its use. COMPLIANCE The responsible party for this device’s compliance is LG Electronics Alabama, Inc.; 201 James Record Road, Huntsville, AL, 35813. WM0742HGA...
TRAINING MANUAL WM0742HGA WM0742HGA SAFETY NOTICES (The Small Print Page) Contents Specifications Warranty Features Controls Fuzzy Logic Door Lock and Indicator Lamp Load Sensing Function Water Circulation Parts Identification (Callout) Accessories Installation Shipping Bolts Leveling Feet Connections Water Drain Electrical Pedestal Installation Control Panel Program Chart...
TRAINING MANUAL WM0742HGA Disassembly and Repair, continued Tub and Drum Dampers Turbo Steam Generator Removal / Replacement Input Check Valve Water Level Sensor Wiring Diagram Low Water Sensor High Water Sensor Hall Sensor Test, Diagnosis, and Repair Hall Sensor Wiring Diagram Tall Sensor Testing Voltage Testing Hall Sensor at Stator Control Board Testing Location...
TRAINING MANUAL WM0742HGA INTRODUCTION The WM0742HGA is a top-of-the-line front-loader with the optional cycles of Allergiene™, Steam, and Tub Clean. SPECIFICATIONS WM0742HGA Page 4 TRAINING MANUAL...
TRAINING MANUAL WM0742HGA WARRANTY Warranty statements vary by product. Be sure to check the warranty that was included with the product because that is the valid warranty. This statement is generic and for instructional purposes only. WM0742HGA Page 5 TRAINING MANUAL...
TRAINING MANUAL WM0742HGA FEATURES LARGE CAPACITY The larger drum (4.2 cu. ft. IEC) allows higher head drop, greater centrifugal force, and washing of larger and heavier loads and oversized items (comforters, curtains, blankets, etc.) There is less wrinkling and tangling of the laundry. (See BULKY / LARGE, page 21.) DIRECT DRIVE The brushless DC motor drives the drum directly without belts,...
TRAINING MANUAL WM0742HGA FEATURES, continued BUILT-IN HEATER The internal heater helps maintain the water at its optimal temperature for selected cycles. The SANITARY cycle kills most common germs and bacteria. The ALLERGIENE cycle is not quite as hot but kills most dust mites and other allergens in laundry. (See additional information on page 39.) CHILD LOCK This allows the user to lock the controls.
TRAINING MANUAL WM0742HGA FUZZY LOGIC To get the best washing performance, the user selects one of the standard cycles. Sensors in the WASHER make an infinitely variable number of adjustments as the cycle progresses. Adjustments are automatically made for load size, incoming water temperature, soil level, rinses required, and other variables.
TRAINING MANUAL WM0742HGA LOAD SENSING FUNCTION In order to determine the size and weight of the load, the machine begins each cycle by tumbling the load a couple of times. It spins up to approximately 120 rpm for approximately 6 seconds. (Speed and time may vary by model.) Determining the size and weight of the load allows the...
TRAINING MANUAL WM0742HGA WATER CIRCULATION The recirculation pump circulates the water during most of the cycle. During the WASH cycle, it runs continuously for the first 3 minutes and then intermittently throughout the cycle. During the RINSE cycle, it runs continuously as soon as the appropriate amount of rinse water has been added.
TRAINING MANUAL WM0742HGA PARTS IDENTIFICATION The air vent on the back of the machine must be left open and clear at all times. If the washer and dryer are installed in a closet or closed laundry alcove, there must be sufficient clearance and ventilation.
TRAINING MANUAL WM0742HGA ACCESSORIES The washer comes with the two input hoses. The blue stripe is for cold water and the red stripe is for hot water. The hoses are not mechanically identical. It is critical to the performance of the washer to have the hot and cold hoses connected correctly. The hot hose is a thicker material suitable for higher temperatures and pressure.
TRAINING MANUAL WM0742HGA INSTALLATION REMOVE THE SHIPPING BOLTS. LEAVE THEM WITH THE CUSTOMER. The lower right bolt is equipped with a clip that secures the cord so it is impossible to plug in the machine without removing the bolt. The cord is further secured by an adhesive sticker which must be broken to free the cord to plug in the machine.
TRAINING MANUAL WM0742HGA CONNECTIONS WATER Be sure the rubber washer is inside the hose end. Attach the hoses to the washer (red is HOT, blue is COLD). Tighten them firmly but don’t strip the plastic threads on the washer connections. The HOT hose is thicker and has a higher temperature rating and burst strength.
TRAINING MANUAL WM0742HGA INSTALLATION (PEDESTAL KIT) This procedure covers installing and leveling the 7½” and 13” pedestals for 27” washers, dryers, and combos. If the products are stacked, the washer must be below the dryer, and only one pedestal is required. Remove the pedestal, installation hardware, and instructions form the shipping carton.
Page 18
TRAINING MANUAL WM0742HGA PEDESTAL, continued Depending upon the model, your pedestal may have straight or curved brackets. The curved ones are to be used on the rear positions when mounting a dryer to a pedestal, but can also be used in any other position on the pedestal.
TRAINING MANUAL WM0742HGA CONTROL PANEL The control panel is located on the front of the Washer. All options are available from the control panel. The ESTIMATED TIME remaining is shown in the window. This may fluctuate during the cycle because the washer will make numerous adjustments based on fuzzy logic and the data supplied by various...
TRAINING MANUAL WM0742HGA PROGRAM CHART This chart shows the components and their times of operation in the various wash cycles. The time estimates shown here are for the basic cycles before the fuzzy logic adjustments are made. See the cycle and option chart on the following page. BEFORE PERFORMING SERVICE •...
TRAINING MANUAL WM0742HGA CYCLE and OPTION CHART See also the section covering PROCESS TECHNICAL INFORMATION on pages 89 and 90 of this training manual. WM0742HGA Page 19 TRAINING MANUAL...
TRAINING MANUAL WM0742HGA CYCLE and OPTION INFORMATION OPTIONS (in general) Every option is not available on every cycle. For example, steam and extra high spin cannot be selected with the HAND WASH/WOOL or DELICATES cycle. Similarly, certain hotter wash temperatures cannot be selected if that would be inappropriate for the materials or cycle selected.
Page 23
TRAINING MANUAL WM0742HGA ALLERGIENE™ The Allergiene™ cycle is designed to use hotter wash water (140° F or 60° C) than the regular HOT wash (112° F or 50° C) but not as hot as the SANITARY cycle (158° F or 70°...
Page 24
TRAINING MANUAL WM0742HGA PERM. PRESS The permanent press cycle defaults to a 0:57 cycle time. The default selections can be overridden for wash temperature, spin speed, and soil level. Water level defaults to approximately 234, which is more water than a normal cycle. DELICATES The delicate cycle defaults to a 0:42 minute cycle.
Page 25
TRAINING MANUAL WM0742HGA SPIN ONLY The SPIN ONLY cycle is not shown on the console. To engage SPIN ONLY, Press POWER and then SPIN SPEED. The COTTON / NORMAL LED will light. The machine will default to a 0:13 minute cycle on high speed unless EXTRA HIGH SPIN is selected, which will increase cycle time to 0:17.
Page 26
TRAINING MANUAL WM0742HGA select the desired cycle and options (as described above,) and then press and hold the CUSTOM PROGRAM for at least 3 seconds, until it beeps twice. Thereafter, simply press POWER, CUSTOM PROGRAM, and START to use this cycle. TUB CLEAN The TUB CLEAN cycle is designed to use extra hot water and a long wash cycle to remove soap scum and residue from the inside of the tub.
TRAINING MANUAL WM0742HGA WATER TEMPERATURE CONTROL PREWASH CYCLE Cold water is supplied via the dispenser when the prewash valve opens. If COLD WASH / COLD RINSE is selected, the heater is not activated. If another WASH / RINSE temper- ature is selected, the heater still is not activated during the PREWASH unless the water temperature is lower than 85°...
Page 28
TRAINING MANUAL WM0742HGA Prewash valve opens, cold water is supplied. B, D, and F Hot valve opens to raise the water temperature to 131° F. C, E, and G Cold valve opens to lower the water temperature to 122° F. No water is supplied because the water level reaches the target.
TRAINING MANUAL WM0742HGA DISPENSER The dispenser is a multi-chambered reservoir that allows the user to add all the appropriate laundry additives before starting the cycle. It has a place for pre-wash detergent, main wash detergent, fabric softener, and bleach. Powdered or liquid detergents may be used, but softener and bleach must be liquids.
Page 31
TRAINING MANUAL WM0742HGA Liquid fabric softener and bleach are dispensed from siphon boxes. As the appropriate chamber is flooded, the water flushes the laundry product into the tub where it is mixed with water before contacting the laundry to prevent spotting or damaging the fabric. The siphon boxes are designed to hold a liquid laundry product until the appropriate time for dispensing into the load.
TRAINING MANUAL WM0742HGA DIRECT DRIVE MOTOR The motor is a direct-drive, brushless, DC motor. It is attached to the drum via a splined shaft, eliminating belts, pulleys, transmissions, and the inherent problems associated with them. The rotor is attached to the shaft by one large bolt. The DC motor can be driven from stopped to maximum speed in infinite steps in either direction.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR The following pages will show the instructions for disassembly, repair, replacement of parts, and re-assembly. Many times, electrical components may be tested by connecting the appropriate meter to the leads or connectors on the main PC Board. (Refer to the block wiring diagram, below.) Proper diagnosis will eliminate unnecessary labor and expedite repairs.
TRAINING MANUAL WM0742HGA DISASSEMBLY/REPAIR (Control Panel) CONTROL PANEL Remove the 7 screws on the back cover of the control panel. Remove the rear cover. Roll the control panel forward. Lay a towel or soft cloth on the washer to prevent damage to the control panel.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued DISPENSER Remove the 5 hose clamps. If you squeeze them and slide them a couple of inches down the hose, they will not be lost while the repair is made. Pull the 5 hoses off the connectors on the dispenser.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued FRONT COVER Remove the control panel and top cover as shown on page 32 and set them aside. Open the filter and drain cover. Remove the screw securing the cover and pry the cover out with a screwdriver or putty knife.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued FRONT COVER, continued Remove the two screws that secure the top of the front cover. Be careful that the front does not fall forward, causing injury or damage. Set it aside face down on a blanket or protective surface.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued PUMPS and FILTER HOUSING Remove the front cabinet. (See page 36.) Drain the water from the sump. Remove the clamps and hoses. Remove two screws and push the pump backward and up. Press down the plastic tab on the base to slide the pump assembly backward.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued DRAIN PUMP, continued The drain pump and the circulating pump are attached to either side of the filter housing. The drain pump is used to exhaust the water from the washer. The recirculating pump serves three purposes: it sprays water from the tub onto the laundry, creating a better saturation of detergent and better rinsing, it keeps the window clean, and it allows the customer to see water in the tub.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued WATER LEVEL SWITCH The water level detector switch monitors the water level and feeds this information to the main board. The sensor reads air pressure in an air chamber on the tub. The air pressure changes in relation to the depth of the water, moving a diaphragm in the switch.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued MOTOR Remove the back cover. Remove the large bolt in the center shaft. DO NOT stick a screwdriver or other object through the slots in the rotor. Pull the rotor off the shaft. Remove the ground screws and wire retainers from the stator wires.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued TUB and DRUM Removing the tub/drum assembly is major surgery. It is much lighter if you remove the weights and the motor. Generally speaking, you’ll have to remove all that anyway. Remove the motor. (See page 40.) Drain the water from the sump.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued DAMPERS Disconnect the dampers from the tub and the base. (See photos, left.) Be sure to press in the safety tab before pushing the pin out of the damper. You can use a socket to hold the tab in while you squeeze the pin with the special tool 383EER4003A.
TRAINING MANUAL WM0742HGA DISASSEMBLY and REPAIR, continued TURBO STEAM GENERATOR The TSG (Turbo Steam Generator) is supplied as an assembly only; parts like the sensor, thermistor, or heater cannot be replaced individually. Diagnosis is limited to determining malfunction and replacing as an assembly. The steam generator does not have to be removed from the machine to be drained.
TRAINING MANUAL WM0742HGA When the Turbo Steam Generator is installed in the washer, the hoses to the dispenser should fit into the tubing guides. Be particularly careful when removing and replacing the water input hose to the steam generator. There is a check valve that fits into the input port.
TRAINING MANUAL WM0742HGA Sensor Wiring Diagram Steam Generator The Steam Generator is made up of 5 major components. They are the 1,100 watt heater @ 120 V , the low water sensor, the high water sensor, the temperature sensing thermistor, and the water tank. The water level sensors, the thermistor, along with the control board determine IF the steam generator heater will be activated.
TRAINING MANUAL WM0742HGA High Water Sensor Sensing Low Water The photo to the left shows the high water sensor (Violet) wire. As the caption shows the meter is reading a voltage of 4.09 V Water in the housing is not touching the high water probe.
Page 49
TRAINING MANUAL WM0742HGA The steam generator heater is shown on the previous page. The heater operates on 120 V @ 1,100 Watts. The amperage is approximately 9 amps. The wiring shows a gray wire (L1) and a red wire (Neutral.) When STEAM is selected or a TUB CLEAN cycle is selected, the control board will verify a high water level, add water via the cold valve if needed, and then energize the heater.
TRAINING MANUAL WM0742HGA HALL SENSOR TEST, DIAGNOSIS, and REPAIR Check the wiring diagram for your machine. The wiring diagrams on some washing machines were incorrect in depicting the hall sensor wiring. The error involves wiring terminal designation. See the diagrams below. The correct wiring terminal colors are: White is (+) Gray is (-)
Page 51
TRAINING MANUAL WM0742HGA Hall Sensor testing methods are now available on the following pages when LE error code hall sensor is out of order or defective. troubleshooting says “ ” Test FIRST!! 1 – BL (Ha) 2 – RD (Hb) 3 –...
TRAINING MANUAL WM0742HGA Terminal Designation / Ohm & Voltage Specifications Hall Sensor Testing The hall sensor can be tested from the control board or at the hall sensor. Ohm Testing the Hall Sensor If tested off the stator using the diagram on the previous page, ohm check the resistors from pin 5 to pin 1 and pin 2.
TRAINING MANUAL WM0742HGA Testing the Hall Sensor from the Control Board Control Board Testing Location Control Board Output and Hall Sensor Input can be measured with the connector connected to the board and the machine operating. Also, these voltages can be measured by parking the meter leads on the desired terminals and spinning the tub briskly with the power cord disconnected.
TRAINING MANUAL WM0742HGA Actual Terminal Wiring The potting epoxy has been removed to show the PC board and components. Voltage Testing Hall Sensor at Control Board (See page 50.) 1. Unplug the power cord. 2. Remove the rear control panel cover. 3.
TRAINING MANUAL WM0742HGA TEST MODE The steam washer must be empty and off to enter the test mode. 1. Press and hold SPIN SPEED and SOIL LEVEL. 2. Press POWER. The buzzer will sound twice. 3. Press START/PAUSE to cycle through the test modes. (See chart, below.) Number of times Event Display...
TRAINING MANUAL WM0742HGA ERROR DISPLAY If you press START/PAUSE when an error code is displayed, any error except PE will disappear and the machine will revert to PAUSE status. In the cases of a PE, TE, or DE error code, if the error is not cleared within 20 seconds, the machine will be turned off automatically and the error code will blink on the display.
Page 57
TRAINING MANUAL WM0742HGA ERROR CODES, continued WM0742HGA Page 55 TRAINING MANUAL...
TRAINING MANUAL WM0742HGA DIAGNOSIS and CHECK LIST (Abnormal Operation), continued OVERSUDSING, NO SOFTENING, ERROR CODES WM0742HGA Page 58 TRAINING MANUAL...
TRAINING MANUAL WM0742HGA TIPS and TRICKS HOSES When replacing the large hoses, be sure to avoid getting the lip turned under the hose clamp. This will damage the hose and cause a leak. The large hoses have notches on the ends to index them on the connectors.
TRAINING MANUAL WM0742HGA PARTS LIST The parts list was correct at the time of publication, but change is inevitable. Always check GCSC for the current and accurate part numbers and availability. Loc # Part No Description *001 AFN30385127 Owner's Manual *002 3890EZ3617A Shipping carton...
Page 75
TRAINING MANUAL WM0742HGA Loc # Part No Description A440 6601ER1004C Switch Assembly, Locker A450 EBR42923401 Main Board A485 6201EC1006A Filter (Noise) Assembly F110 6871EC2123J PCB Assembly, Display F120 6877ER1015P Harness, Multi F140 6877ER1016F Harness, Multi F145 6877ER3003B Harness, Single F160 5221EA1009B Valve Assembly, Inlet Cold, 5-way F170...
Page 76
TRAINING MANUAL WM0742HGA Loc # Part No Description K122 4280FR4048J Bearing, Ball (Outer) K123 4040FR4051C Bolt Assembly K125 4036ER2004A Gasket K130 4866ER0007A Balance Weight (Top) K131 1SZZER4002A Screw, Custom K135 4866ER0004A Balance Weight (Bottom) K140 3551ER0026J Tub, Outer (Front half) K141 4036ER4001B Gasket (Between tub halves)
TRAINING MANUAL WM0742HGA SERIAL NUMBER IDENTIFICATION The serial number is unique to each product. It gives information concerning the time and place of manufacture. The serial number is required to be paid for warranty service and to get the correct part in the event a running production change was made. Some models may have four (4) letters instead of two (2) for the product code number.
TRAINING MANUAL WM0742HGA OHM’S LAW and WATT’S LAW P = WATTS I = AMPERES Watts = Volts x Ohms Amperes = Volts / Ohms Watts = Amperes x Ohms Amperes = Watts / Volts Watts = Volts x Amperes Amperes = E I •...
Page 80
TRAINING MANUAL WM0742HGA CONVERSION INFORMATION FORMULAE °F = (9/5) °C + 32 °C = (5/9) x (°F – 32) WASH TEMPERATURES STAIN CYCLE Adds cycle time and increases wash Sanitary 158° F (70° C) temperature Allergiene 140° F (60° C) 122°...
TRAINING MANUAL WM0742HGA PROCESS TECHNICAL INFORMATION Standby * The washer is plugged in but turned off. Water Supply * Drum rotates and fill begins after a cycle is selected. * If PREWASH is selected, cold water is supplied via the PREWASH valve.
Page 92
TRAINING MANUAL WM0742HGA Process Technical Information, continued Rinse Spin * The water remaining in the load is extracted by centrifugal force while the drum is spun at the selected speed. Remaining Spin * The power to the motor is cut off and the drum continues to spin by inertia until it stops.