16008373-01

1998 Maytag Corporation

INSTALLATION

1. Two separate red shipping straps are used to secure the machine for shipping purposes and to secure the power cord with the water inlet hoses. Remove the straps in the following sequence:
A. Locate the metal buckles securing the red straps which extend through slots in the rear wall of the cabinet. The buckles are positioned in the center of the red straps. Carefully cut the red straps, and remove the metal buckles. NOTE: Cut the straps as close to the buckles as possible. Discard the buckles. 3.

Figure 1-2

Locate the two (2) " hex head shipping bolts extending up through the bottom of the base (Figure 1-4). The shipping bolts are near the center of the base toward the front of the washer. Remove both bolts, freeing the tub and suspension. Do not be alarmed should the tub assembly shift when the last bolt is removed. Some shifting of the tub is normal.

Figure 1-1

B. Grasp each loose strap individually and pull the strap to remove it from the cabinet. Discard the strap (Figure 1-2). 2. Tip washer slightly forward. Loosen rear leveling leg lock nuts. Tip washer back slightly to loosen front leveling leg lock nuts (Figure 1-3).

Figure 1-3

Turn on the water and check for leaks (Figure 1-5). Note the H and C designations on the water valve bracket for the Hot and Cold hoses.

Figure 1-4

Figure 1-5
Slide the washer into position and check the levelness and stability of the washer. If necessary, slide the washer out of position to either raise or lower the leveling leg as required to level and stabilize the washer securely on all four legs. Slide the washer back into position to confirm levelness to the floor. When the washer is level, tighten the locking nuts up against the base of the washer. This will secure the leveling legs in place. Install the rubber feet, found in the installation package, on all four (4) legs (Figure 1-3). Pull the drain hose vertically to the drain strap. Then route the drain hose through the drain hose strap on the back of the washer and snap into the plastic hook of the strap. Install gooseneck end of drain hose into drain standpipe. Be sure the connection is not airtight between the drain hose and standpipe. Standpipe must be at least 24" high. 36" height is recommended. Connect inlet hoses to water supply using screen washers (found in the installation package) at faucet connections, with the domed screen facing the faucet. Attach hoses to the faucets and the water valve.

TACH INPUT The tach input is a feedback signal from the motor control. It provides eight pulses per revolution of the switched reluctance motor. The motor runs at 14 times the speed of the spinner (14:1 belt ratio). The tach input is used for monitoring speed and out-of-balance detection (See Tachometer Circuit Diagnostics). If the machine control commands a motor speed and direction but does not sense a tach input signal within five seconds, it will disengage the line relay to stop the washer. This generally indicates a locked rotor or a malfunction in the motor control. If the machine control senses a tach input signal when it is not commanding the motor to run, it will disengage the line relay to stop the washer. If the machine control commands a coast down from final spin speed but is still receiving a tach input signal after two minutes, it will disengage the line relay to stop the washer. TEMPERATURE SENSOR INPUT A thermistor is located in the water valve to monitor the blended incoming water temperature. The machine control uses this input signal to regulate the water temperature with the warm or cold wash or warm rinse temperature selections (See Water Valve Outputs). TIMER INPUTS The Timer Input signals are energized through the cams in the timer. The timer operates with a 30 second drive cycle and a 5.8 second advance time (See Timer Input Charts). WATER TEMPERATURE INPUTS The Water Temperature inputs are two separate signals defined by a user input switch on the control panel. The machine control interprets these signals to determine what the water temperature should be for each fill (See Water Valve Outputs).

OUTPUT DEFINITIONS

DOOR LOCKED LIGHT OUTPUT NOTE: This section applies only to washers between Series 10 and 16. The "Door Locked" lights on washers from Series 17 and after are controlled by a "Door Locked" light switch. The Door Locked Light Output signal powers a 1/3 watt neon indicator lamp on the control panel. This output is first energized when the Door Lock Wax Motor Output is energized. At the end of the cycle, it remains energized for 50 seconds after the Door Lock Switch Input shuts down. This delay allows the wax motor to fully retract and unlock the door. NOTE: The washer will continue to tumble at the end of cycle until this 50 second delay is elapsed. DOOR LOCK WAX MOTOR OUTPUT The Door Lock Wax Motor Output signal powers a wax motor in the door lock assembly. The wax motor extends to drive the door lock system for the washer. If the washer is started with the timer set in a Prewash Tumble, Main Wash Tumble, or Light Wash Tumble increment, the machine control will wait for three minutes before energizing the Door Lock Wax Motor Output. This delay is not affected by water level. This output remains energized until the end of the cycle. If the washer is started with the timer set in a Prewash Drain, Bleach Dispense, Spin1, Rinse Tumble, Spin2, or Spin3 increment, the machine control will energize this output immediately. The machine control will continuously energize the Door Lock Wax Motor Output during the final (Spin 3) sequence until 30 seconds before the washer begins to coast from the final speed.

Digital Test Meter can be used to check for open or closed circuits, measure resistance, AC and DC volts, and temperature.
AC Voltage Sensor can be used to alert you if AC voltage is present so proper safety precautions can be observed. The tip of the sensor will glow bright red if voltage is between 110-600 volts AC.
SECTION 2. 1998 Maytag Corporation

ELECTRICAL TESTS

Warning - Always shut off electrical power to the unit before beginning any service repair procedures.

Water Valve Test

Check the water valve for electrical continuity. This check should be made with the electrical supply disconnected from the washer. Remove the wire harness from the water valve terminals and place the ohm meter probes on the terminals of the water valve. The water valve solenoid coil should have a resistance between 500-1000 ohms. If no ohms are shown on the display of the electrical test meter, the solenoid coil has an open winding and the valve should be replaced. The thermistor in the water valve changes in resistance in direct relationship to water temperatures. To monitor the performance of the thermistor, run a partial hot water fill and check the ohm resistance of the thermistor circuit. Then, run a cold water fill and measure the resistance again. There should be a notable difference in the resistance readings. To check the ohm resistance, pull the P2 wire harness connector off the machine control and locate the P2(5) and P2(6) leads in the connector (Figure 2-3).

Grounded

Components
When performing service diagnostics, replacements and repairs, always check to determine whether all ground wires linking panel and components are reattached if removed.

Voltage Checks

Generally, these checks will consist of taking readings at the wall receptacle to determine the availability of voltage to the product. Voltage checks on individual components of a product are not recommended due to the possibility of electrical shock. Component part testing is best accomplished through continuity checks with an Appliance Test Meter (See Electrical Test Equipment). NOTE: Use of the meter on voltage higher than the indicated range may cause permanent damage to the meter. To prevent damage, first select the highest range and then lower the range for readings which fall within the lower scale. Set up meter for use as follows: 1. 2. 3. 4. Turn selector knob to desired meter function and appropriate range. Plug black lead into socket marked black (-). Plug red lead into socket marked red (+). Place test leads into receptacle to determine voltage available.

Timer Input Charts

As stated previously, the machine control board receives inputs from the timer monitor where the timer is in the cycle. The machine control board accomplishes this by routing four circuits through the timer. Two of the circuits (1A & 1B) are supplied with 120 VAC and the other two circuits (2A & 2B) are 24 VDC. The voltages for the four circuits is shown on the timer chart of the electrical schematic enclosed in the washer console.
SECTION 2. ELECTRICAL COMPONENTS & TESTING 1998 Maytag Corporation
Software in the machine control board specifically monitors the timer input circuits to determine where the timer is in all the wash cycles and will rapidly advance the timer to OPEN and break contacts in the timer. The timer is solely used as an off-board set of relay switches. Note: The timer motor is hard wired to timer cams 10T and 10B in the timer.
TIMER 1A (120 VAC) PK19/P7(8) TIM ER 1B (120 VAC) YL16/P7(7) TIMER 2A (24 VDC) PU17/P3(3) TIM ER 2B (24 VDC) BU18/P3(5) 0 0
CYCLE SEQUENCE PREWASH TUM BLE PREWASH DRAIN MAIN WASH TUM BLE LIGHT WA SH TUM BLE BLEACH DISPENSE RINSE TUMBLE SPIN 1 SPIN 2 SPIN 3 EXTRA RINSE DELAY IDLE
0 = Input Signal Not Asserted

1= Input Signal Asserted

There are conditions under which the machine control will shut the cycle down if the timer does not advance. During Extra Wash/Prewash: If the timer inputs do not change away from Prewash Tumble for 15 minutes, the machine control will open the line relay. During Main Wash: If the timer inputs do not change for 29 minutes, the machine control will open the line relay. During any increment when the machine control energizes the timer motor until it sees the timer inputs change: If the timer inputs do not change for 5 minutes with the timer motor continuously energized, the machine control will open the line relay.
These varying delays are to allow the washer to progress through several increments where the timer inputs normally do not change. In these cases, the machine control energizes the timer motor for 30 seconds, which is its advance time. It does not look for a timer input change.
16008373-01 SECTION 2. 1998 Maytag Corporation ELECTRICAL COMPONENTS & TESTING

Machine Control

The machine control microprocessor board is located in the control console, mounted to the rear panel. The board receives input from the timer, door latch and lock switches, and unbalance and selector switches on the console. It also communicates with the motor control board to facilitate the various cycles and drive the motor for optimum performance. Torque and speed of the motor are monitored through the motor control board.

Prior to Series 17

Figure 2-3

Series 17 and After

Figure 2-3b
Both incoming and exiting voltage are monitored through the machine control board and the surrounding circuitry. The following table lists the voltages for the various terminals on the microprocessor board. If proper voltage is not present, check switches and wiring for any loose connections or open circuits by disconnecting the power supply and performing continuity checks of individual circuits. NOTE: Connector P5 is Neutral input and L1 input is the Line Relay Connector Comm (Gray wire), L1 output is Line Relay Connector Comm (Black wire). To check voltages from the board, turn timer dial to a wash cycle and press the start/off button. This will activate the L1 relay board and apply power on the machine control.

16008373-01 SECTION 2. ELECTRICAL COMPONENTS & TESTING 1998 Maytag Corporation

FU N CTIO N

M A C H IN E CON TROL BOARD T ERM IN A L/ W IRE P5 (W H11)
M A C H IN E CON TROL BOARD T ERM IN A L/ W IRE P3/2 (PK 37)
V O L T A G EAPP R O X. (W hen A ct i v a t e d ) 24 VDC

T IM ER C O N TACT

Permanent Press (Fab ric Sw i tch ) Delicates (Fab ric Sw i tch ) H a n d W ash (Fab ric Sw i tch ) C o t t on/ S t urd y (Fab ric Sw i tch )

N o t Inv o lv e d

P5 (W H11)

P3/6 (OR 38)

24 VDC

P3/8 (BR 39)

P5 (W H ) P5 (W H ) P5 (W H ) P5 (W H )
P3/2 (PK 37) P3/6 (OR 38) P3/8 (BR 39) P2/1 (PU 21)
0 VDC 0 VDC 0 VDC 24 VDC - O N 0 VDC - O FF 120 VA C
Signal O N / O FF ( O p t i o n s S w i t ch ) Extra Rin se ( O p t i o n s S w i t ch ) M ax Extract ( O p t i o n s S w i t ch ) Push To Start Sw it ch (When pressed) U nbalance C o nt r o l D o o r Lock - Sp in M ot o r Control & M a ch in e C o nt r o l H o t W ater V a l v e

P5 (W H )

P7/8 (PK 19)

12B, 6B ,8T

P2/3 (Y L 20)

P1/3 (RD 28)

120 VA C

P2/4 (OR 40)

P3 (1) P5 (W H11)
P3/7 (Y L 36) LIN E RELA Y C O M (BK 27 or BK1) P7/1 (OR7)

24 VDC 120 VA C

N o t Inv o lv e d N o t Inv o lv e d
120 VA C o r 500-0 O h m s 120 VA C o r 500-0 O h m s 120 VA C
C o ld W a t e r V a lv e

P7/2 (BU 9 )

D o o r Lock W a x M ot o r Bleach W a x M ot o r S o ft e n e r W ax M ot o r D e l a y L ight O n Li g ht (S e r ies 17)

P7/4 (BR 14)

N o t Inv o lved

P5 (W H11) P5 (W H11)

N o t Inv o lved P7/5 (RD 3)

120 VA C 120 VA C

4T N o t Inv o lv e d

DRIVE MOTOR

The drive motor is a switched reluctance type motor. The basic operating principle of the switched reluctance motor is direct magnetic attraction between the stationary electromagnetic coils (stator) and a specially configured rotor or armature (Figure 2-4). The rotor is comprised of stacked plates or laminations mounted on a center shaft. The shape of these laminations are characteristic of the switched reluctance motor. The rotor, when viewed from the end of the rotor, has "teeth" much like a gear. These "teeth", or pole pieces, are pulled as the result of direct current power through the stator coils.
The following illustration shows the motor terminals for each of the coils involved. The letters with positive and negative symbols indicate the motor phase circuitry of the terminals.

Motor Harness Connector

6. If the motor runs, and the spinner rotates at the proper RPM speed, the problem lies outside of the motor and motor control circuit. Disconnect power to the washer and reconnect the JP4 Interface connector to the motor control. 7. If the motor does not run: A. Check the 10-amp fuse located on the control board, either visually or with an ohm meter. If bad, completely replace motor control/wire harness assembly (Figure 2-6). B. If the fuse is functioning, visually check the six semiconductors on the heat sink for any damage. If damaged, replace motor control/wire harness assembly complete and check motor windings for damage (See Drive Motor). Replace motor if necessary(Figure 2-6). C. If fuse and semiconductors show no visible damage, perform the motor phase test. 8. Unplug the washer power cord and replace motor control board connector JP4 when finished.

Test Motor Phase Test

It is possible for the motor to still run under light loads when one of the phases of the motor is nonfunctional. One possible symptom would be a "growling" noise from the motor. Torque is decreased when the motor is out of phase. This could result in a customer complaint that the load is not spinning out properly or it does not tumble consistently Tr with a large load (See Section 3: Tr oubleshooting).

Figure 2-6

To gain access to the motor control board terminals (Figure 2-6): 1. Disconnect power to the washer prior to testing. 2. Remove the two screws securing the motor control assembly to the base. Unsnap the two twist-lock wire ties restraining the motor to the motor control board harness base. 3. Remove the green ground wire, line & neutral wires and the JP4 connector from the motor control board. 4. Carefully lift the front end of the motor control board to disengage the rear locking tabs from the slots in the base. Slowly drag the motor control board, with motor harness attached, toward the front of the washer and place in front of the washer. 5. Remove the screw securing the splash shield covering the face of the motor control board. Pivot the splash shield with top screw in the motor control board metal frame, allowing the plastic shield to become an electrical shield between the motor control board and the base. 6. Reconnect the ground wire, line 1 and neutral wires. Leave the JP4 connector off the board (Figure 2-6). 7. Place the timer knob into the delay increments. 8. Plug the power cord into the wall socket and press the push-to-start button. Check Phase C by disconnecting the yellow or orange wire at the motor control board. If the motor operates with a slight growling sound, phases A and B are operating correctly. Reconnect phase C and test with phase B disconnected. If the motor does not run properly, phase A or B is not functioning. Perform the motor

4 Remove the front panel and top cover (See. Front Panel & Top Cover Removal). 5 Disconnect the hoses attached to the dis. penser assembly. 6 While lifting, rotate the dispenser assem. bly 90 degrees in a counterclockwise direction. NOTE: The two tabs on the side wall of the dispenser bottom may break off if the above procedure is not followed properly.
5 Remove the hose clamp and injector hose. from the spout on the front upper area of the outer tub. 6 In order to provide sufficient space to re. move the injector, place a 5/8" - 3/4" wedge between the spinner and the outer tub. 7 Pinch the two tabs exposed on the outer. edge of the outer tub spout and press the injector into the tub. Reverse the previous steps to replace the injector.
PUMP FRONT WATER FLUME INJECTOR
As water is filling the dispenser assembly, water is also diverted to a hose leading to the front of the outer tub. As the water enters the top of the outer tub through the hose, it passes through a water flume. The flume directs the water toward the front of the tub to saturate the clothes load.

Figure 6-5

ASSEMBLY
The pump assembly is mounted to the right rear area of the base.
1 Disconnect power to the unit. 2 Spread a towel below the drain hoses prior. to loosening the hose clamps. This will catch any residual water left in the hoses and sump area. 3 Remove the hose clamps and hoses from. the pump. 4 Remove the wiring harness from the pump. motor terminals. 5 Rotate the pump assembly in a counter. clockwise direction. The support legs of the pump are slotted to engage in keyed slots in the base. Reverse the steps to remount the pump.
1 Disconnect power to the unit. 2 Remove the front panel and raise the top. cover to expose the upper front cabinet area (See Front Panel & Top Cover Removal). 3 Remove the front shroud assembly (See. Front Shroud Assembly Removal). 4 Remove the outer tub cover (See Outer. Tub Cover Removal).

Figure 6-6

Figure 6-7
CLEANING THE PUMP The pump assembly can also be disassembled without removing the hoses from the pump (See Figure 6-6). 1 Depress the locking tab on the face of the. pump housing. 2 Rotate the block portion of the pump con. taining the motor windings toward the front of the washer. This will disengage the locking tabs of the pump housing from the pump face. 3 Carefully remove the pump body away. from the housing. The drain impeller is exposed for cleaning. 4 Position the second pump near the first. pump and connect the accessory connector to the sump intake of the second pump. Secure with the clamp in the kit. 5 Connect the drain hose to the drain outlet. of the second pump. Secure with a clamp. 6 The second pump assembly is not secured. to the washer's base frame. 7 Installation is complete.

START/PAUSE INPUT The start/pause input is selected on the membrane switch for both washers. If this input is initially selected the machine control will begin the wash cycle sequence as defined by the user input selections. If this input is selected when a cycle is in progress, the machine control will pause the cycle and unlock the door when it is safe to do so. (Note: Machine control board is powered up all the time. There no longer is a line relay used, as opposed to the MAH3000, 4000 and 5500A models.) TACH INPUT The tach input is a feedback signal from the motor control. It provides eight pulses per revolution of the switched reluctance motor. The motor runs at 14 times the speed of the spinner (14:1 belt ratio). The tach input is used for monitoring speed and out-of-balance detection (See Tachometer Circuit Diagnostics). If the machine control commands a motor speed and direction but does not sense a tach input signal within 2 or 3 seconds, it will assign a HELP code number and perform 10 retries. If unsuccessful, this generally indicates a locked rotor or a malfunction in the motor control. If the machine control commands a coast down from final spin speed but is still receiving a tach input signal after two minutes, it will log appropriate service codes.
OUTPUT MODIFICATIONS DEFINED
DOOR LOCK/UNLOCK SOLENOID OUTPUT The Door Lock/Unlock Solenoid Output signal is a 60 millisecond pulse sent to a solenoid in the door lock assembly. The solenoid is attached to a lever which moves a slider in the mechanism to lock the door after it has been closed and the cycle started. The solenoid has two coils, one for locking and one for unlocking when a pulse is directed to specific terminals on the solenoid. Power is not continuously applied to the solenoid, because this would damage the solenoid. END-OF-CYCLE SIGNAL OUTPUT The End-Of-Cycle Signal Output is an internal signal on the machine control between the microprocessor and annunciator. The end-of-cycle signal sounds when a wash cycle is finished. The end-of-cycle signal sounds as four pulses on the MAH5500B and 3 pulses on the MAH7500 in a 0.5 second intervals. If the door is opened right at the end of the cycle or during the end of cycle beeps, then the signal will stop on the MAH5500B only. If the start/pause key is pressed near the end of the cycle, the end of cycle signal will not occur unless the cycle is restarted and allowed to finish. If the Off key is pressed, the end of cycle signal will not occur. The end of cycle signal will occur when the door is unlocked and ready to open on the MAH5500B. On the MAH7500, the signal sounds then the door is unlocked. HEATER OUTPUT (LCD Washer only) The machine control board turns the heater on to heat the wash water during the main wash until the temperature reaches the targeted main wash temperature. The heater is turned back on at any point the temperature falls 5 F

Trigger

Action to be Taken
Unlocking attempts disallowed because tach signal continues after tach verification Door locked when not expected C abinet impact sensed Door did not lock after the first try
Motor running and Perform Diagnostic Motor/Motor the door is not locked C ontrol Board test. C heck wire harness connections at motor, motor control board (JP4 connector) C ycle was paused Informative only; Refer to Diagnostic due to failure to verify code 62 (LC D Only) tack signal during unlock request C ycle was paused Informative only; Refer to Diagnostic because motor code 62 (LC D Only) control not powered during unlock request Informative only; Refer to Diagnostic C ycle was paused code 62 (LC D Only) because the tach occurred when the motor control was powered during unlock request No tach signal Informative only; Refer to Diagnostic observed when code 62 (LC D Only) motor control is powered at the end of the failed fast powerup and unlocks retries C heck door lock switch for welded contacts C abinet impact Informative only detected by the frame vibration sensor The door lock switch C heck for loose wire connections and did not go from for bad door lock sense switch unlocked to locked when the door lock output was energized
DIAGNOSTIC CODES LISTING:
D iag. Co d e 01 D escription No drain Trigger The water level fails to drop below the low water level in final spin Action to be Taken LED - W ill display "nd" LC D - Display washer will not drain C heck for: Restricted drain system Kinked/plugged drain hose or pump Faulty pump Loose wire connections Bad control board LED - W ill display "LO" LC D - Display washer will not unlock C heck for: Faulty door lock solenoid Loose wire connections Faulty door lock switch Faulty door lock sense switch Bad control board LED - W ill display "nF" LC D - Display washer will not fill C heck for: C logged inlet screens Water Available Loose wire connections Pressure switch contacts Bad control board LED - W ill display "FL" LC D - Display washer will not lock C heck for: Faulty door lock solenoid Loose wire connections Faulty door lock switch Faulty door lock sense switch Bad control board C heck for: Faulty unbalance switches Loose wire connections Bad control board LED - W ill display "Lr" LC D - Display motor is not working C heck for: Perform Diagnostic motor/motor control test Loose wire connections BInded spinner shaft bearings C heck for: (LC D only) Loosed wire connections to heater and thermistor Faulty thermistor Faulty heater Perform System C heck (page 14)

The door fails to unlock

Door failed to unlock after 11 attempts

No fill

C ontinuous fill of 12 minutes.

The door fails to lock

First Rinse This is the first rinse following the main wash portion of the cycle. Key Any Membrane switch or touchscreen keypad. Key press Any membrane switch key press or touchscreen press. Non-tempered cold This will only have the cold water valve energized. Non-tempered warm This will have both the cold water valve and the hot water valve energized. Non-tempered hot This will only have the hot water valve energized. Plaster This is the point at which the centrifugal force of the spinning action is greater than the force of gravity so that the clothes no longer tumble, but are kept plastered against the spinner. User activity Any key press or door opening or closing. Redistribution As the machine is accelerating into spin, if it detects that the clothes load is unbalanced and would cause excessive vibration, it will decelerate and tumble the clothes in an attempt to redistribute them in a more uniform manner so that vibration is reduced. Softener water valve This is the coil and valve assembly that allows water to enter the fabric softener dispenser when this coil is energized. In order for water to flow, this coil needs to be energized in conjunction with a fill water valve.
Spin This is the process of rotating the clothes at a high speed so that the centrifugal force extracts the water from the clothes so that it can be drained from the machine. Spin Speed This is the speed of the washer spinner during extraction. Spinner This is the wash basket that holds the clothes and is turned by the motor. Static Drain This is a drain with no tumble action. Tempered This refers to fills which cycle the cold or hot water valve to achieve a desired final temperature. Tumble This is the process of rotating the clothes in one direction for a time, pausing for a period and then reversing direction and repeating this action. The speed of the spinner is slow enough so that the clothes are being tumbled (i.e. lifted out of and dropped back into the water/detergent solution).
Tumble Flush This is a tumble at a higher tumble speed than normal while the machine is filled with water. The purpose of this function is to clean the machine, mix detergent and during the final rinse to reduce chance of suds creation. Tumble Speed This is the speed of the washer spinner. Tumble drain When the drain pump is on while the machine is tumbling at the specified tumble pattern for the cycle. Wrinkle Free This is both a type of fabric selection (such as with cotton/sturdy, Delicates, and Hand Wash) and a spin speed setting.
SECTION 4. ELECTRICAL COMPONENTS & TESTING
Warning - Always shut off electrical power to the washer before beginning any service repair procedures.

Door Lock Test

The door lock can be verified by the following procedure. LED Model 1. Place the washer into Service Mode. (See Section 2; Accessing Service Mode) 2. Advance to the Board Output Test and press Max Extract to Lock the door and Extra Rinse to Unlock the door. LCD Model 1. Place the washer into Service Mode. (See Section 2; Accessing Service Mode) 2. Select Service Tests, then Quick Spin Tests to actuate the door lock mechanism. Hit Cancel to unlock the door. Note: The relay on the control board for the door lock mechanism is disabled if the motor control board indicates the spinner speed is > 7 RPM. For more information related to door lock mechanism, please refer to Section 2: Miscellaneous; Door Lock Philosophy.

Grounded Components

The water valve test is similar to the test outlined in the 16008373 manual, except, to check the ohm resistance of thermistor, pull the P3 wire harness connector off the machine control and locate the P3(6) and P3(7) leads in the connector on the machine control board. Note the thermistor has been relocated on the valve to the outlet of the valve. (See Figure 4-1) Fabric Softner Cold Hot Bleach
Thermistor 4 Coil Water Valve Figure 4-1 The thermistor is on NTC and will drop in resistance when the temperature increases.
16010486 (16008373-05) Revised 02/01 Section 4. Electrical Components & Testing 2001 Maytag Appliances Sales Company
DOOR LOCK MECHANISM Door Lock/Unlock Solenoid Emergency Cord Rotating Cam Door Open/ Cam Door Lock Closed Switch Mechanical Support Spring Opener
Figure 4-2 Machine Control The machine control microprocessor board is located in the control console, mounted to the plastic console. The board receives input from the membrane pad/touch screen, door lock switches, and the unbalance switches. The control also communicates with the motor control board to facilitate the various cycles and drive the motor for optimum performance. This is done by monitoring torque and speed of the motor through the motor control board.
Figure 4-3 Both incoming and exiting voltage is monitored through the machine control board and the surrounding circuitry. The following table lists the voltages for the various terminals on the microprocessor board. If proper voltage is not present, check switches and wiring for possible loose connections or open circuits by disconnecting the power supply and performing continuity checks of individual circuits. NOTE: Connector P8(2) (White wire) is Neutral input and L1 input is the connector P6(2) (Black wire), L1 output is connector P6(3) (Black wire). The machince control board outputs can be verified by placing the washer into the Service Mode and performing a Board Output Test. (See Section 2; Service Mode; Board Output Test.)
INPUT/OUTPUT VOLTAGES (LCD Washer)
D escription Bleach water valve output C hassis Ground C old water valve output Door Lock output Door lock switch input Door switch input Door unlock output Drain pump output Heater - Neutral High water level - input Hot water valve output L1 to machine control board L1 to motor control Lower water level - input Motor control tach Neutral (120 VAC ) Unbalance input Softener water valve Sump thermistor Torque PW M Water valve thermistor Co n n e c t o r / Pin Number P1(5) P3(1) P1(4) P1(1) P2(3) P 8 (1 ) P 8 (3 ) P6(4) P6(1) P1(8) P 1 (3 ) P6(2) P6(3) P2(3) P2(1) P8(2) P2(3) P1(6) P5(3) P2(2) P3(6) P3(4) P8(2) P5(4) P2(3) P3(7) P8(2) P8(2) P3(8) P8(2) P8(2) P8(2) P8(1) P8(2) P 8 (2 ) P 8 (2 ) P8(2) P3(5) P2(3) Co n n e c t o r / Pin Number P8(2) Voltage 120 VAC Ground 120 VAC 120 VAC 24 V DC 120 VAC 120 VAC 120 VAC 120 VAC 120 VAC 120 VAC 120 VAC 120 VAC 24 V DC 24 V DC Neutral 24 V DC 120 VAC V DC 24 V DC 5 V DC 10K-85K ohms) NTC device (see thermistor temperature chart - page 4-8 LC D model only (3K-18K ohms) 500 - 1K ohms MAH7500 Only (~14 ohms) 60 millisecond pulse 500-1K ohms 60 millisecond pulse Co m m e n ts

The motor control is able to determine the motor's position by monitoring the active phases in the motor. This is done by sending pulse signals to the motor and then timing the echo signal. By doing this, the motor control is able to deterimine the motor speed and direction. This information is then calculated to determine the motor speed. The motor control has a software switch in it that will turn off all power devices for as long as the main voltage is above 133 VAC. Once the mains voltage drops below that voltage, the power devices will be re-enabled and the motor control will resume normal operation.

Motor Control Access

Slight modifications were made to the motor control bracket and the plastic drip shield. Drip Shield Removal 1. Push the plastic shield on either side of the locking tab to buckle and unlock the shield from the motor control bracket. (Figure 4-4) Motor Control Board Removal 1. Pull the vertical tab forward and lift the front of the motor control board and slide the control forward to lift and remove the control from the bracket. (Figure 4-5)
2. The motor control board bracket is secured with two screws in front and secured to the baseframe via a tab on the bracket inserted into a slot in the baseframe. Figure 4-4
Motor Drive System Test To check the system, check the board for proper output to the motor control. This is done by performing a board output check. Then perform the Motor And Motor Control Test. Machine Control Board Output Test 1. Place the washer into Service Mode. (See Section 2; Accessing Service Mode) 2. LED Washer: Access Board Output Test and press Stain Cycle. This will send a signal to the motor control to operate the motor. This will test the board relay for 120 VAC output to the motor control board. Motor will not operate, because the door is not locked. LCD Washer: Access Service Tests and press system check. Touch the screen to toggle the motor control on. This will test the board relay for 120 VAC output to the motor control board. Motor Phases With the introduction of the sensorless motor, the Motor Phase Test is no longer required. If the motor experiences a phase problem, the motor will not run. Motor & Motor Control Test 1. Disconnect power to the washer. 2. Remove the front panel and pull the JP4 Connector from the motor control board. (Figure 4-6) 3. Reconnect the washer power cord to supply voltage. 4. Press Help and Back function to activate Service Mode. Figure 4-6 5. LED Washer: Select Board Output Test; close door or push door acturator button; touch the stain cycle membrane switch. LCD Washer: Select System Check; close door or push door actuator button: touch Toggle Motor Control On 6. The motor control will immediately execute a test routine and the motor should run, rotating the spinner at 50 rpm. 7. If the motor runs, and the spinner rotates at the proper RPM speed: the problem lies outside of the motor and motor control circuit. Disconnect power to the washer and reconnect the JP4 Interface connector to the motor control. If the motor runs, and the spinner does not rotate: Check for missing belt. 8. If the motor does not run: a. Check the 10 amp fuse located on the control board, either visually or with an ohm meter. If bad, replace motor control/wire harness assembly completely. (Figure 4-7)

Section 5. Teardown & Wiring Information
The door lock mechanism is now locked and unlocked via solenoids, resulting in faster locking and unlocking of the washer door. The mechanism is a non-repairable assembly and must be replaced as an assembly.
An Emergency Access Cord is available and is accessible by removing the dispenser bezel. The nylon cord is located and pulled in a direction away from the lock area. The cord is attached to the mechanical opener. When the cord is pulled, the opener will pivot and push the locking lever into the open positon.
DOOR LOCK MECHANISM Door Lock/Unlock Solenoid Emergency Cord Rotating Cam Door Open/Closed Cam Door Lock Switch Mechanical Support Spring Opener
Figure 5-7 Removal 1. Disconnect power to the washer. 2. Remove the front panel, dispenser bezel and lift the top cover to expose the door lock assembly. 3. Remove the individual wire harnesses from the assembly and the two mounting screws. 4. Roll the top of the door lock assembly forward and lift from the front shroud assembly.
Section 5. Teardown & Wiring Information 2001 Maytag Appliances Sales Company

REAR ACCESS PANEL

5. Locate and loosen the valve mounting screw by turning the screw at least three full turns. Removal of the access panel gains access to
the rear components of the washer (Figure 5-9).
NOTE: The mounting screw serves as a locating pin to hold the valve in position on the mounting bracket. By partially removing the screw, the water valve can now be slid to the left and removed from the bracket (Figure 5-10). 6. Carefully lift the valve with the inlet hoses attached and direct the inlet hoses through the openings in the valve mounting bracket.

WATER SYSTEM COMPONENTS

7. The hoses can be crimped or the water shut off at the faucets. Place a towel below the valve and remove the inlet hoses from the water valve.
WATER VALVE The water valve is accessible from the front of the machine. The flow rate of the valve is 4 gpm. Removal 1. Discontinue power and water to the machine. 2. Remove the front panel and lift the top cover. 3. Remove the wire harness connections to the water valve solenoids. 4. Loosen and remove the hose clamps on the inlet hoses leading away from the water valve.