Maytag MDB8751AW', MDB7751AW', MDB8951AW', MDBM755AW', ADB3500AW User Manual

Dishwasher — Technical Information

ADB3500AW*, MDBM755AW*, MDB7751AW*, MDB8751AW*, MDB8951AW*

• Due to possibility of personal injury or property damage, always contact an authorized technician for servicing or repair of this unit.

• Refer to Service Manual 16021814 for detailed installation, operating, testing, troubleshooting, and disassembly instructions

All safety information must be followed as provided in Service Manual 16021814.

CAUTION

To avoid risk of electrical shock, personal injury, or death, disconnect power to dishwasher before servicing.

Benefits ADB3500AW* MDBM755AW*

MDB7751AW*

Wash cycles 5 4 6 5 Heavy Wash X X X X Normal Wash X X X X Quick Wash X Light Wash X X X Insta Wash X X Auto Clean X X

Rinse Only X X X X

Features Sound package

High Temp

Wash Electronic Controls Sanitizer X X X Sensor clean X X X X

Water Filtration

Delay Start Energy Star X X X X

Hard Food Disposer Child lockout X X X X Touch Pad Controls Silverware Location Low rinse aid indicator

Sofsound III™

X X X X X X X X

100% Filtered wash

water

2,4 or 6 Hour Delay

Start

X X X X

10 7 12 13

In door

QuietSeries™

Micro-Fine Plus

2,4 or 6 Hour

Delay Start

Compartment

WARNING

200

Filtration

Wash

MDB8751AW* MDB8951AW*

QuietSeries™

300

Micro-Fine Plus

Filtration

1-9 Hour Delay

Start

Wash

Compartment

QuietSeries™

400

Micro-Fine Plus

Filtration

1-9 Hour Delay

Start

Wash

Compartment

Component Specifications

WARNING

To avoid risk of electrical shock, personal injury, or death, disconnect power to dishwasher before servicing.

Specifications Value

Power Source

Voltage AC 120 VAC Amperage (Single Unit) 15 A Frequency 60 Hz Motor horsepower

1/3

Height−overall

Weight

Dimensions

33 ½” to 35 ¼”

Illustration Component Test Procedure Results

Dishwasher Motor CCW rotation only

viewed from shaft end.

1/3HP 120V/60hz, 3.2 amps, 3250 RPM Main Wattage, 285 watts Start Wattage, 1115 watts Control Panel See Component Specifications/

Measure resistance from ST5 (Motor Common – blue) to ST8

(Motor Main - yellow) .........................

See Component Specifications/Motor Connections for details.

Membrane Readings for troubleshooting/pin-out instructions.

3 to 4 Ω

Water valve 120V/60hz, 7 watts

1.13 ± .10 gpm at 20120 psi

Vent wax motor 120V with 1/4"

actuation stroke within 90 seconds

Measure resistance from J6 Pin 4 Aqua (Float switch) to ST4

Black (Common) ...............................

Measure resistance from J6 Pin 1 Purple (Vent) to ST4 Black (Common)

...........................................................

1.1 k Ω (This value assumes the float switch is closed).

1.2 k Ω

Component Specifications

WARNING

To avoid risk of electrical shock, personal injury, or death, disconnect power to dishwasher before servicing.

Illustration Component Test Procedure Results

Dispenser wax motor 120V with 1/4"

actuation stroke within 90 seconds

Limit Thermostat

Measure resistance from J6 Pin 3 Tan (Dispenser) to ST4 Black

(Common) .........................................

Close on Temperature drop @ 149°F

± 7°F (Temp) .......................................

Open on Temperature drop @ 164°F

± 4°F (Temp) .......................................

2 k Ω

0 Ω = Closed Infinite Ω = Open

Sensor/Thermistor

10KΩ ± 3% at 77°F and 2.4 k Ω ±

6.5% at 140°F J5 pin 1 - Orange (Temp) to J5 Pin 4 -

Red (Neutral) .......................................

Heater/Heating Element

120v/60hz, 650 watts ± 5% in air, 830 watts ± 5% in 90°F water

Drain Motor 120v/60hz

45 watts

Measure resistance from ST1 Red/Black (Heater) to ST11 White

(Common) ...........................................

Measure resistance from ST6 Gray (Drain) to ST4 Black

(Common) ...........................................

Infinite Ω = Open 0 Ω = Closed

16 Ω (This value assumes the high limit thermostat is closed).

25 Ω

Component Readings/Testing

WARNING

To avoid risk of electrical shock, personal injury, or death, disconnect power to dishwasher before servicing.

A Manual Func ti on Test may be st arted by pressing the key 5 times fol l ow ed by the key within8 seconds.

The LED will 3 times indicating manual test mode is

Normal W ash Flash

active. Specific ke y pads will turn on or off a component a s fo ll o w s:

Hi Temp Wash Wash Mot or Hi Temp Wash

Heated Dry Heating Element Heated Dry

Cycles Select / Normal

First Press No Action Heavy Wash

Second Press Dispenser Normal Wash

Third Press Drain Pump Light Wash / China Cryst al

The test will cancel 120 seconds after the last keypad is pr essed. The display (if available) will show ‘99’ until the remaining timeout period is less than 99 seconds. At this point it will countdown until the mode times out, is cancelled, or another key is pressed. To cancel test, press the keypad.

To check control LED’s and components, enter . If control fails to perform sequence as described, and a fault is detected, determine failure as described in the . If a load component failure has been diagnosed, proceed to the . To check individual load com p o ne nts for proper operation, enter . Follow test procedure as described. Repair or replace component as neede d.

: The or may be detected during

Note High Current Low Current Motor Error

a wash cyc l e selected by a consu mer. If this happe ns, the control will go i n t o a 30 second auto restart mode and shut down if the unit is not able to restart the motor.

Manual Func tion Test

Start

KEY Function LED

Delay Water Inlet Valve Delay

, Field Servic e Test

Diagnostic Tips

Field Service Test

Manual Function Te st

Manual Function Test

Heated Dry

Start / Cancel

Membrane Readings

(All Models)

Heavy Wash Normal Wash Light Wash / China Crystal / Gentle Wash Quick Rinse Only Auto Clean / Sensor Clea n Heated Dry Sanitize Hi Te mp Wash

Connector

J1 J1

J1 J1 J1 J1 J1 J1

Measu r e Between

Pin 9 - Pin 5 Pin 9 - Pin 6

Pin 9 - Pin 7

Pin 9 - Pin 8 Pin 10 - Pin 5 Pin 11 - Pin 5 Pin 11 - Pin 6 Pin 11 - Pin 8

(Front Only Controls)

Cycle Select Start / Cancel Delay T ough Scrub Plus / Su per Scrub / Power Sc ru b T ough Scrub / Extra Wash / Hi Temp Insta Wash Model ID Jumper

An unpressed switch will read as an open circuit. A pressed switch wi l l read as 10 k . * On select mo dels



Connector

J1 J1 J1

J1 J1 J1 J1

Measu r e Between

Pin 9 - Pin 5 Pin 10 - Pin 6 Pin 10 - Pin 7 Pin 10 - Pin 8 Pin 11 - Pin 7 Pin 12 - Pin 5 Pin 12 - Pin 7

A Field Service Test may be started by pressing the key 6 times followed by the key within 8 seconds. This test must be performed with clean water to insure proper sensor performance.

“88” will appear in the di splay (if available*) and the follo wing sequence of events will occur:

SECONDS

The time for the Thermistor chec k / Turbidy Sensor che ck & calibration may vary slight ly.

The Field Service Test will not repeat. The LED will during the test mo de. All I nd i cator lights (except ) will illum inate. If the dishwasher door is opened during the test, the test sequence will pause, and resume when the door is closed. To cancel test, press the keypad.

The cont r ol has been designed to test the Sensor Memory and Motor. During the F ield Servi ce Test, i f a fault has been detected, the test will abort any time after the m ot or current has been checked and 2 or more LED ' s wil l begin to

Flash Memory / Software Check

start ed. The LED and one of t he following:

* On select models

Insta Wash Tough Scrub Plus / Super Scrub / Power Scrub 160° Wash Tough Scrub / Extr a Wash / Hi Temp Model ID Jumper Start / Ca nc el Delay

Start

106

5 120 180

120

. A will occur immediately after the test is

(Delay / Delay 2 hr)

* *

(Top Only Controls)

Insta Wash Tough Scrub Plus / Super Scrub 160° Option Tough Scrub / Extr a Wash / Hi Temp Model ID Jumper Start Cancel Delay

Field Serv i c e Test

FUNCTIONS / ACTIVE LOADS Vent Wax Motor / Water Valve Thermistor check / Turbidity Sensor check & calibration - no loads active. Wash Motor / Vent Wax Motor / Dispenser Wax Motor Wash Motor / Heater / Vent Wax Motor Drain Pump Water Valve

Heavy Wash

Turbidity Sensor Hi Temp Wash Thermistor Heavy Wash Motor Normal Wash

- high current - LED

Motor Light Wash

- low current - LED

Memory Failure Heated Dry

- failure - LED

- failur e - LED

- LED

Heated Dry

Heavy Wash Flash

the

Start / Cancel

Membrane Readings

(Front & Top Controls)

J1 J1 J1 J1 J1 J3 J3

J1 J1 J1 J1 J1 J1 J1

Measur e B et w e e n

Pin 10 - Pin 6 Pin 10 - Pin 7 Pin 10 - Pin 8 Pin 11 - Pin 7 Pin 12 - Pin 8

Pin 9 - Pin 5 Pin 9 - Pin 6

Measur e B et w e e n

Pin 10 - Pin 6 Pin 10 - Pin 7 Pin 10 - Pin 8 Pin 11 - Pin 7

Pin 12 - Pin 6 Pin 13 - Pin 12 Pin 13 - Pin 14

Connector

Load Readings

Heater¹ Wash Motor Drain Motor Dispenser Wax Motor Water Valve² Thermistor

Notes:

1. This value as su mes the high limit th er m ostat is closed.

2. This value as sumes the float swi tch is cl osed.

3. Results are approximated values.

ST5 (Motor Common ) - ST8 (Motor Main)

Measure Betw een

ST1 (Heater) - ST11 (Dlb Neutral)

ST6 (Drain) - ST4 (Dlb Line)

J6 Pin 3 (Di sp ) - ST4 (Dlb Lin e)

J6 Pin 4 (Inlt) - ST4 (Dl b Li ne)

J5 Pin 1 (Temp) - J5 Pin 4 (Neutral)

Result



3 to 4



1.1k

See Comp on ent Info

Electrical Diagnostics

WARNING

To avoid risk of electrical shock, personal injury, or death, disconnect power to dishwasher before servicing.

*** A resistor in the control board wired in parallel will result in an approximate reading of 4.0 k ohms

with connector J5 plugged in.

** Nominalvalueforohmsof electrical resistance of component only. Thesevalueswillvary slightly

due to the additional resistance of the wire harness. Greater variation can occur if the component is

still warm from being energized during testing.

Perform the resistance checks on the component(s) in question at the locations shown on the chart.

* Select ModelsOnly.

(A white plastic latch must be inserted in the latch assembly for this test.)

> With one ohm meter lead connected to the white (neutral) power lead, you should have continuity at

stakelugs10&11.

> With one ohm meter lead connected to the black (line) power lead, you should have continuity at

stakelugs3&4,andpin#8onconnectorJ5.

To check continuity from ends of power leads to control board through door switches

Use the "Manual Function Test" as described on the electrical schematic sheet to

check components before

Pin#12345678 Pin#1234 StakeLug11109876 54321

OR RD RD AQ PU BK PU TN AQ

opening the door to perform continuity testing or replacing parts.

J5 J6

connector unplugged)***

2.4K* +/- 6.5% @ 140 10K* +/- 3% @77

*Vent WM

(1.2K**)

Resistance Check Points and Values

Thermistor (thru harness only with

Disp. WM

(2K**)

Circuit Board

mustbe closed)

WH WH

before performing any resistance or

Always

YL GY BU BK B K RD

continuity checks.

remove power to the unit

(High limitt'stat must

(14.5 - 16.5**)

be closed)

Heater

Wash Motor

(3 - 4**)

(25**)

Water V alve

(float switch

(1.1K**)

Drain Motor

Control Definition

To avoid risk of electrical shock, personal injury, or death, disconnect power to dishwasher before servicing.

Designed to provide a longer cycle for washing items with heavy food soils. water usage is 8 gallons.

Designed to wash loads containing dishes with normal amounts of food soils. Water usage ranges from 3 to 6 gallons.

Designed for light food soils. The cycle ends with a rinse and does not include drying. water usage is 4 gallons.

Rinses dishes being held until the dishwasher is full, and another cycle is selected. This cycle helps reduce the potential for developing odors. Water usage is 2 gallons.

Light Wash- Designed to wash loads containing dishes that are lightly soiled Water usage is 5 gallons. Insta Wash- Designed to wash loads containing dishes that are lightly soiled Water usage is 5 gallons. Auto Clean- Designed to auto select the number of fills and length of wash times based on soil level of dish load.

Water usage ranges from 3 to 8 gallons.

Tough Scrub- This option adds fills, heat and/or wash time to the wash cycle.

Designed to auto select the number of fills and length of wash times based on soil level of dish load. Water usage ranges from 3 to 8 gallons.

WARNING

Delays the start of the dishwasher based on user selection.

This option improves drying results by turning the heating element on and off during the dry portion of the cycle.

This option monitors cycles for sanitization.

This option raises Temperature in the

Final rinse to 160

° F

Control Definition/Motor Connectivity

To avoid risk of electrical shock, personal injury, or death, disconnect power to dishwasher before servicing.

120V/60hz, 3.2 amps, 3250 RPM

WARNING

Green

Yellow

Blue

(Common)

1/3HP

(Start)

(Ground)

(Main)

Wire harness Connection plug

Cycle Chart

To avoid risk of electrical shock, personal injury, or death, disconnect power to dishwasher before servicing.

1. All times are approximate.

2. Temperature checks force a maximum 20 minute heating delay to reach the desired temperature.

3. The cycle definition gives the minimum and maximum possible cycle lengths. Actual cycle length and executed cycle functions will vary based on the sensor input.

4. Fill length varies between different models.

Auto Clean/Sensor Clean

Sanitize Sanitize Light Wash

160° Option 160° Option

Temperature Options (Available on select models)

adds 5 minutes unheated circulation prior to rinse aid dispen se.

Notes

: If the option is available for a given cycle, it for ces a 140°F temp check at the end of the main wash for the , a 154 °F temp check prior to the rinse aid dispense in the final rinse, and

SENSOR CLEAN CYCLE

AUTO CLEAN CYCLE/

(128 Minutes - max)

(94 Minutes - min)

: If the is available for a given cycle, it forces a 160°F temp check prior to the rinseaid dispense in the final rinse.

1:46 max

1:36 min

FILL

WASH

PRE

8:00

DRAIN

2:20

Available Options:

Hi Temp Wash

Tough Scrub/

Tough Scrub Plus Tough Scrub

Extra Wash/Hi Temp

- This option has no effect on this cycle.

/Super Scrub/Power Scrub

- This option adds an additional 5 minutes of heated wash to the wash

1:46 max

- This option is the same as but the main wash temp check is boosted to 145°F.

HEATED

8:00

(133 Minutes - max)

WASH

2:20

(132 Minutes - min)

1:36 min

HEAVY WASH CYCLE

PRE

DRAIN

Tough Scrub Plus/Super Scrub/Power Scrub Tough Scrub

FILL

- This option is the same as but the main wash temp check is boosted to 145°F.

HEATED

SKIP?

1:46 max

1:36 min

FILL

DISP

DET

HEATED

WASH

25:00

CHECK

TEMP

140°F

DRAIN

2:00

1:46 max

1:36 min

FILL

HEATED

RINSE

10:00

PRE

1:46 max

1:36 min

FILL

HEATED

WASH

8:00

main and a 10 minute heated pre- r inse.

DISP

DET

HEATED

WASH

22:00

CHECK

TEMP

140°F

DRAIN

2:00

1:46 max

1:36 min

FILL

WARNING

Available Options:

Hi Temp Wash

Tough Scrub/Extra Wash/Hi Temp 5

- This optio n ov e r rides the sensor’s decision to sk i p cycle functions / modify temp checks and adds an additional minutes of heate d wash to the ma in wash.

NORMAL WASH CYCLE

(117 Minutes - max)

(97 Minutes - min)

- Overrides the sensor’s decision to modify the temp checks and skip a rinse.

1:46 max

1:36 min

FILL

HEATED

WASH

PRE

8:00

DRAIN

2:20

SKIP?

1:46 max

1:36 min

FILL

DISP

DET

HEATED

WASH

26:00

HEATED

WASH

SKIP?

2:00

SEE NOTE

CHECK

TEMP

TC 1

DRAIN

2:00

1:46 max

1:36 min

FILL

Available Options:

Hi Temp Wash

Tough Scrub/Extra Wash/Hi Temp

Tough Scrub Plus/Super Scrub/Power Scrub Tough Scrub

- This option is the same as but the main wash temp check is boosted to 145°F.

GENTLE WASH/QUICK WASH

CHINA/CRYSTAL CYCLE/

82 Minutes - Max

81 Minutes - Min

- This option boosts the final rinse temp check to 145°F.

- This optio n ad ds an 8 minute pre-wash and 5 minutes of heat ed wash to the main wash.

1:46 max

1:36 min

FILL

DISP

DET

HEATED

WASH

10:00

DRAIN

2:00

1:46 max

1:36 min

FILL

HEATED

RINSE

10:00

DRAIN

2:00

1:46 max

1:36 min

FILL

HEATED

RINSE

15:00

CHECK

TEMP

140°F

Available O p tions:

Only the option is available with the cycle.

LIGHT WASH CYCLE/

INSTA WASH CYCLE

Heated Dry Insta Wash

51 Minutes - Max

20 Minutes - Min

1:46 max

1:36 min

FILL

DISP

DET

HEATED

WASH

4:00

DRAIN

2:00

1:46 max

1:36 min

FILL

HEATED

RINSE

2:00

DRAIN

2:00

1:46 max

1:36 min

FILL

HEATED

RINSE

3:00

DRAIN

2:00

Available Options:

No options are available with the cycle.

RINSE ONLY CYCLE

9 Minutes

Rinse Only

1:46 max

1:36 min

FILL

RINSE

5:00

DRAIN

2:00

FILL

0:02

HEATER