Maytag MDG9800, MDE DG5500 User Manual

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Atlantis_Neptune_Electric_and_Gas_Dryer_Service_Manual

Appliance 911

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MDG9800
MDE9800
MDE6800
MDG6800
MDE7000
MDE7600
MDG7600
MDE8600
MDG8600

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3-2

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8-5

SECTION 9 - DRYER CONTROLS OVERVIEW ......................................................................... 9-1

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DRYER CONTROLS OVERVIEW ............................................................................................ 9-1

BASIC CONTROL BOARD PHILOSOPHY FOR BOTH DRYERS ............................................ 9-1

BASIC MACHINE OPERATION ............................................................................................... 9-2

LED DRYER CONTROL SELECTIONS .................................................................................... 9-3

DRYER TEMPERATURE CONTROL ....................................................................................... 9-5

SPECIAL FEATURES ............................................................................................................... 9-6

SERVICE/DIAGNOSTIC MODE .............................................................................................. 9-6

LED DRYER ............................................................................................................................. 9-7

LCD DRYER ............................................................................................................................. 9-9

SYSTEM CHECK ................................................................................................................... 9-10

DIAGNOSTIC/HELP CODES ................................................................................................. 9-10

CONTROL CONFIGURATION MDE/MDG6800, MDG5500 ..................................................... 9-12

SERVICE MODE MDE/MDG6800, MDG5500 ......................................................................... 9-12

MEMBRANE PAD CHECK MDE/MDG6800, MDG5500 ........................................................... 9-12

SYSTEM CHECK MODE MDE/MDG6800, MDG5500 ............................................................. 9-12

DIAGNOSTIC CODES MDE/MDG6800, MDG5500 ................................................................. 9-13

MEMBRANE PAD CONTINUITY CHECKS MDE/MDG6800, MDG5500 ................................... 9-14

SERVICE MODE MDE/MDG7500, MDE/MDG9800 ................................................................ 9-15

USER INTERFACE MDE/MDG7500, MDE/MDG9800 ............................................................. 9-16

MEMBRANE PAD CHECK MDE/MDG7500, MDE/MDG9800 .................................................. 9-16

SYSTEM CHECK MDE/MDG7500, MDE/MDG9800 ................................................................ 9-16

DIAGNOSTIC/HELP CODES MDE/MDG7500, MDE/MDG9800 .............................................. 9-16

MEMBRANE PAD CONTINUITY CHECKS MDE/MDG7500, MDE/MDG9800 .......................... 9-17

SECTION 10 - ELECTRICAL SCHEMATICS ............................................................................ 10-1

MDE3000 ............................................................................................................................... 10-1

MDG3000............................................................................................................................... 10-2

MDE4000AZ, MDE8000AZ .................................................................................................... 10-3

MDE5000AZ .......................................................................................................................... 10-4

MDG7057............................................................................................................................... 10-5

MDG6000, MDG7000 ............................................................................................................ 10-6

MDE6000AZ, MDE7000AZ.................................................................................................... 10-7

MDE4000AY, MDE8000AY .................................................................................................... 10-8

MDE6000AU/AY, MDE7000AY .............................................................................................. 10-9

MDE7057AY ........................................................................................................................ 10-10

MDG4000AW/AX/BW, MDG8000AW/BW ......................................................................... 10-11

MDE5500 ............................................................................................................................. 10-12

MDE5500 (Canada) ............................................................................................................. 10-13

MDG5500............................................................................................................................. 10-14

MDE7500 ............................................................................................................................. 10-15

MDE7500 (Canada) ............................................................................................................. 10-16

MDG7500 ............................................................................................................................. 10-17

MDG6200 ............................................................................................................................. 10-18

MDE7600 ............................................................................................................................. 10-19

MDG7600 ............................................................................................................................. 10-20

MDE7600 (Canada) .............................................................................................................. 10-21

MDE8600 ............................................................................................................................. 10-22

MDE8600 (Canada) .............................................................................................................. 10-23

MDG8600 ............................................................................................................................. 10-24

MDE6200 ............................................................................................................................. 10-25

©2000 Maytag Appliances Sales Company

Contents

v

MDE6200 (Canada) .............................................................................................................. 10-26

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MDE6800 ............................................................................................................................. 10-27

MDG6800 ............................................................................................................................. 10-28

MDE9800 ............................................................................................................................. 10-29

MDG9800 ............................................................................................................................. 10-30

©2000 Maytag Appliances Sales Company

Contents

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MDE/DG5500 Facia (LED Screen) MDE/DG7500 Facia (LCD Screen)

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PRODUCT SPECIFICATIONS

Same specifications as outlined in service
manual part number 16009968.

Section 1. General Information

1-7

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INPUT/OUTPUT VOLTAGES

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LCD Dryer

LED Dryer

Description

Heater Relay - Internal
(Output)

L1 Board (Input) BB1(1) BB2(3) 120VAC Door must be closed.

Motor (Input) BB1(2) BB2(3) 120VAC Door must be closed.

24 VDC (Input) BB1(3) BB1(2) 24VDC (Electric Dryer Only)

Neutral (Input) BB2(2) BB1(1) 120VAC

Heater Relay - External BB2(1) BB2(3) 120VAC

Door Sense BB2(3) BB1(2) 120VAC Door must be closed.

24 VDC (Input) BB2(4) BB1(2) 24VDC

Thermistor J4(1) J4(2) 5VDC

Sensor Bar J4(3) J4(4) 24VDC

Connector

Pin Number

P1 P2 24 VDC

Connector

Pin Number

Voltage Comments

Door must be closed.
(Electric Dryer Only)

NTC
70oF=10K ohms
150oF=1754 ohms

16010279
(16009968-01)

Description

Heater Relay - Internal
(Output)

L1 Board (Input) BB1(1) BB2(3) 120VAC

Motor (Input) BB1(2) BB2(3) 120VAC

Neutral (Input) BB2(2) BB1(1) 120VAC

L1 Board (Input) BB2(1) BB2(3) 120VAC

Door Sense BB2(3) BB1(1) 120VAC

Thermistor J4(1) J4(2) 5VDC

Sensor Bar J4(3) J4(4) 24VDC

Connector

Pin Number

P1 BB1(1) 120VAC

Connector

Pin Number

Voltage Comments

Section 2. Electrical Components & Testing 2-7

Door must be
closed.

Door must be
closed.

Door must be
closed.

Door must be
closed.

NTC
70oF=10K ohms
150oF=1754 ohms

Membrane Pad Checks

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On the MDE/DG5500 dryer you can perform
the Membrane Pad Check with the control
console. (See Section 9: Accessing Service
Mode; Membrane Pad Check)

LCD Dryer

Membrane Pad Pin Number Pin Number

home J7(3) J7(5)

favorites J7(4) J7(5)

back J7(3) J7(6)

start/pause J7(3) J7(7)

off J7(4) J7(7)

help J7(4) J7(6)

LED Dryer

On both dryers, you can check the mem­brane pads, by pulling the J7 connector from
the machine control board and locating the
corresponding switch pin numbers in the
ribbon harness.

Membrane

Pad

Pin Number Pin Number

sensor dry J7(12) J7(13)

time dry J7(11) J7(13)

time (+) J7(10) J7(13)

time (-) J7(9) J7(13)

Dry Temp (^) J7(11) J7(14)

Dry Temp (v) J7(10) J7(14)

Dryness(<) J712) J7(14)

Dryness(>) J7(9) J7(14)

wrinkle release J7(11) J7(15)

press care J7(9) J7(15)

air fluff J710) J7(15)

start/pause J7(11) J716)

signal (-) J7(12) J7(15)

off J7(9) J7(16)

signal (+) J7(12) J7(16)

16010279
(16009968-01)

Section 2. Electrical Components & Testing 2-8

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MODELS: MDE/DG5500, 7500

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CONSOLE WITH MEMBRANE PAD

Warning - Always shut off
electrical power to the
dryer before beginning any

The replacement console assembly consists of
the console, medallion and membrane pad.

CONSOLE REMOVAL

1. Disconnect power to the unit.

2. Remove the four screws securing the
console to the rear cover plate.

5. For reinstallation, reverse the
aforementioned steps.

Figure 4-10

MICROPROCESSOR BOARD
REMOVAL

Figure 4-8

3. Lay a drop cloth across the top cover of the
washer.

4. Grasp the top of the console and gently
rock the top of the console forward away
from the rear console back. Note the
hooked tabs on bottom of the console,
which engage the slots in the top cover.

1. Disconnect power to the dryer.

2. Remove the console assembly.

3. Carefully remove the membrane pad
harness and other wires from the
microprocessor board.

Figure 4-11

16010279
(16009968-01)

Figure 4-9

Section 4. Console Assembly

4-3

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SPECIAL FEATURES

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The LCD and LED dryers come with several
new features not available with the earlier
versions of the Neptune dryers. By pressing
a combination of keys, the dryer can be
placed into an Advertising Mode or into a
Service Mode for the service technician.

ADVERTISING MODE

This mode will continuously display the LEDs
on the keyboard or illuminate the touch
screen.

LED Dryer

Pressing the damp dry and sensor dry keys
for 5 seconds will start the washer in the
Advertising mode. No functions will be run
except illuminating the LEDs.

All the LEDs will light within 1.5 seconds in the
following order and repeat: start/pause, signal,
wrinkle prevent, wrinkle release, air fluff, damp
dry, less dry, normal dry, more dry, very dry,
cool down, wrinkle prevent indicator,
temperatures (regular, medium, low, extra low),
sensor dry, time dry, time(+), time(-), 7
segment display.

While in advertising mode, the display will
cycle through eleven screens. If the touch
screen or any key (except off) is pressed, the
advertising sequence will be interrupted and
the control will go to the Interactive State.

When this occurs, the user is able to navigate
through the control as normal (including
setting favorites, setting preferences, etc.),
but the machine will not be allowed to run a
cycle. The only methods of exiting the
advertising mode is to remove power from
the machine or to press and hold both the
help key and the favorites key for 5 seconds.
The off key will not be active in the service
mode.

After 5 minutes of inactivity in the advertising
mode, the control will time out and return to
advertising mode and the advertising
sequence will begin again. When the control
times out in this manner, any settings or
changes that the user had made while in the
advertising mode will not be remembered.

SERVICE /DIAGNOSTIC MODE

Enter and exit the advertising mode by using
the same 2 key sequence or unplug the
power cord.

LCD Dryer

This mode will continuously display the touch
screen on the keyboard.

Pressing the favorites and back keys for 5
seconds will start the dryer in the Advertising
mode. No functions will be run except
illumination of the touch screen panel.

© 2000 Maytag Appliances Sales Company

This mode provides service personnel the
ability to verify the operation of the dryer.

The service mode can be implemented in the
middle of any dry cycle. While in the service
mode, the servicer can start special service
tests such as a system check mode,
membrane pad check, display software
revision number and display diagnostic/help
code listings. (See Service Mode Table) The
diagnostic/help code information displayed
provides information about the machine.

Section 9. Dryer Controls Overview

9-6

To aid the service technician, special software

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was incorporated into the control boards of
the MDE/DG5500 & MDE/DG7500 dryers. The
software is used to monitor several functions
of the dryer during operation and identify any
abnormalities as they arise. These
abnormalities can be monitored in the
Service Mode and the board will list
previously identified failures as either a Help
or a Diagnostic code.

Press Keys Special Test/Function

wrinkle

release

dryer

temp(^)

dryer temp(v)

Diagnostic Codes

Sequences up the
help/diagnostic code list

Sequences down the
help/diagnostic code list

The Diagnostic codes are identified when the
severity level of the abnormality detected is
higher and service may be required.

Both code lists are stored in separate
permanent memories with a maximum of
nine codes per list.

NOTE: Due to the various differences
in the two dryer control systems, the
following pages will focus first on the
LED dryer then the LCD dryer.

LED DRYER

Accessing Service/Diagnostic Mode:

Pressing down the damp dry and time (-) keys
for 5 seconds places the machine in the
diagnostic mode.

time (-)

very dry(<)

start/pause

Displays Software Revision
Number

View current cycle
temperature (Co)

Start or pause cycle running
but remain in Diagnostic
mode

Diagnostic Codes:

When a problem with the dry system is
detected a diagnostic code is assigned and
logged into the control board memory. An
assigned diagnostic code indicates the dryer
may need to be serviced. The control board
will not log mulitple same codes per cycle,
however, it will log as many diagnostics as
possible for the machine to continue running.

See the diagnostic code table for specific
actions or references to where the proper
action is defined. (See page 15)

Accessing Diagnostic Codes

After the machine is in the diagnostic mode,
a ‘d’ will display and let the technician know
they are in the diagnostic mode. Pressing the
wrinkle release key will access the diagnostic
codes.The diagnostic codes can be viewed by
using the temperature (^) & (v) keys.

SPECIAL TESTS

The following table lists the various tests
available while in the Service Mode, which
can be accessed by pressing the following
keys:

© 2000 Maytag Appliances Sales Company

Section 9. Dryer Controls Overview

9-7

The down arrow key will sequence down the

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list one each time it is pushed with no wrap.
The first time the down arrow key is pushed
the display will sequence to the next code
logged. The last code being displayed being
the oldest code. The up arrow will sequence
up the list one code each time it is pushed
until it reaches the top code. If there are no
diagnostic codes available, ‘00‘ will be
displayed for the diagnostic code.

This mode will allow the various inputs and
outputs to be controlled and viewed by the
technician by pressing individual keys. If no
activity is seen for 5 minutes after a key is
depressed, the control will reset back to the
normal mode. If no further activity is seen
after an additional 5 minutes the washer will
turn off. The following table lists the various
functions based upon on keys being de­pressed.

There will be no multiple occurrences of
either a diagnostic code or help code gener­ated in the same cycle reported on the list.
But if the same code occurs in repeated
cycles, it will be registered.

To clear the diagnostic code list press
wrinkle prevent and very dry (>) for 5
seconds while viewing the list.

System Check Mode

While in diagnostic mode, pressing the damp
dry and signal (+) keys for 2 seconds, will

put the dryer into the system check mode.
"SC" will display.

Key Pressed: Function Performed

Enable sensor dry circuit.
(sense dry LED) When short

sensor dry

start/pause

dry temp(^)

very dry(<)

circuit is detected across the
sensor bars the normal dry
LED will turn on.

Cycles the motor relay
on/off. When the motor is
running the start/pause LED
is on.

If motor is running, cycles

the heater/gas valve on/off.
When the heater is regular
temp LED is on.

View current cycle
temperature (Co)

Membrane Pad Check

While in system check mode, pressing the
damp dry and sensor dry keys for 5 seconds,
will start a membrane pad switch test.

The membrane check involves turning all the
embedded LED on the membrane pad on.
All the LED’s can be toggled off by pressing
the key associated with the LED. To exit the
test at any point, press the damp dry (>) &
sensor dry keys again for 5 seconds or press
the off key to exit diagnostic mode.

Section 9. Dryer Controls Overview

© 2000 Maytag Appliances Sales Company

9-8

LCD DRYER

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User Interface Test:

Accessing Service Mode

Press and hold the back and help keys for 5
seconds to start the Service Mode.

Pressing the Service Mode keys again, will
take the machine out of the Service Mode.

Service Mode

diagnostic codes

user interface test

system check

exit service mode

1...

2...

3...

4...

upper

left

Touch the four corners and center of the touch

lower

left

User Interface

Test

screen in any order.

center

exit user

interface test

upper

right

lower

right

This will check the touch screen. The service
technician is prompted to “Touch the four
corners and center of the touch screen in any
order." When each area is pressed, the
display will reverse image. If all areas are
sensed, the control will display “Touch screen
test passed." If any area(s) is not sensed
within 5 seconds, the technician will be
prompted to “Touch the area(s) not
highlighted." If the area can still not be
sensed within 5 seconds, the control will
display “Touch screen test failed." In either
case scenario, the screen will step to the next
screen to check the membrane switches.

The Service Mode screen lists four different
touch panels; user interface test (membrane
switch test), system check, diagnostic codes
and exit service mode. Pressing any of the
touch screens will activate a different screen
dedicated to that function.

The diagnostic codes listed are the last four
codes assigned by the dryer.

After 5 minutes of inactivity in Service Mode,
the dryer will exit Service Mode and return to
the state just prior to Service Mode. If a
service test is being run, the control will
remain in Service Mode until 5 minutes of
inactivity has occurred at the end of this
cycle.

© 2000 Maytag Appliances Sales Company

User Interface

Test

Touch screen test passed.

Press the 6 members switches in any order.

home

favorites

back

help

start/pause

off

exit user

interface test

This test checks the membrane switches on
the console pad.

The screen displays the status of the touch
screen test that was just performed. The

Section 9. Dryer Controls Overview

9-9

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The membrane check turns all the embedded LED’s on.

ys

DRYER CONTROLS MDE/MDG6800, MDG5500

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Control Configuration

This Trouble Shooting guide illustrates how the software
works with the 13 and 15 key membrane switches. The
section on Accessing Diagnostic Codes includes
instruction for use with older control boards.

13 Key Membrane

15 Key Membrane

Service Mode

This mode provides Service Personnel the ability to
verify the operation of the dryer.

The Service Mode can be implemented in the middle of
any dry cycle. While in the Service Mode, the
Technician can start special diagnostic tests such as a
System Check Mode, Membrane Pad Check, Display
Software version number and display diagnostic/help
code listings.

Enter Service Mode:

Air Fluff

Press

and

Time (^)

- 13 Key Membrane.

or

Air Fluff

and

Time (+)

- 15 Key Membrane.
keys for 3 seconds, or until a beep is heard. The
machine will now be in Service Mode and “d” will be
displayed.

Exit Service Mode

Press the

Air Fluff

Diagnostic Tests

OFF

key to exit Service Mode or repeat the

Time (+)

and

sequence.

The following table lists the various tests available while
in the Service Mode, which can be accessed by
pressing the following keys:

Key Press Special

Test/Function

Wrinkle release

Then press

Temperature (^)

or

- 13 Key

Dry Temp (^) - 15 Key

Display list of
diagnostic codes.

To sequence thru
the diagnostic
and help codes.

Time (v)

- 13 Key

or

Time (-)

- 15 Key

Sensor Dry Level (^)

Key
or
Very Dry (<) - 15 Key

Display revision
number

View current

- 13
cycle temperature
in Celsius

Key Press Special

Test/Function

Start/Pause

Start or pause
cycle running but
remain in
diagnostic mode.

System Check Mode

While in Service Mode, pressing the
Air Fluff and Signal (+) - 13 Key Membrane
or

Air Fluff

and

Signal (+)

- 15 Key Membrane
keys for 3 seconds, will put the dryer into the System
Check mode and "SC" will display. The following table
lists the various functions based on the keys being
pressed.

System Check Mode Table

Key Pressed: Function

Performed

Sensor Dry

Enable sensor
dry circuit (sense
dry LED) when
short circuit is
detected across
the sensor bars
the normal dry
LED will turn on.

Start/Pause

Cycles the motor
relay on/off.
When the motor
is running the
start/pause LED
is on.

Temperature (^)

- 13 Key
or
Dry Temp (^) - 15 Key

If motor is
running, cycles
the heater/gas
valve on/off.
When the heater
is regular temp
LED is on.

Sensor Dry Level (^)

Key
or

View current

- 13
cycle temperature
in Celsius.

Very Dry (<) - 15 Key

Membrane Pad Check

All the LED’s can then be toggled off by pressing the
key associated with the LED.

While in System Check Mode, pressing the

Air Fluff and Sensor Dry - 13 Key
or

Air Fluff

Sensor Dry

and

- 15 Key

keys for 2 seconds, will start a Membrane Pad Switch
Test. To exit the test at any point, press the same ke
again for 2 seconds or press the

OFF

key to exit

Service Mode.

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Section 9. Dryer Controls Overview

© 2000 Maytag Appliances Sales Company

9-12

MDE/MDG6800, MDG5500

disregard the

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Diagnostic Codes

The Diagnostic Codes are identified when the severity
level of the abnormality detected is higher and service
may be required.

When a problem with the dryer is detected a Diagnostic
Code is assigned, and can be displayed. The Control
Board will not log multiple same codes per cycle;
however, it will log as many Diagnostics as possible for
the machine to continue running.

Accessing Diagnostic Codes with 13 Key Membrane

Press Air Fluff and Time (^) to enter Service Mode.
Press the Wrinkle Release key to access the
Diagnostic Codes. Scroll through the Diagnostic Codes
by pressing the Temperature (^) key. The first time the
key is pressed the newest code will be displayed. Each
additional key press shows the next code. Once all the
codes have been displayed a “d” is displayed and the
process repeats. If there are no Diagnostic Codes
available, “00” will be displayed for the Diagnostic Code.

Accessing Diagnostic Codes with 15 Key Membrane

Press Air Fluff and Time (+) to enter Service Mode.
Press the Wrinkle Release key to access the
Diagnostic Codes. Scroll through the Diagnostic Codes
by pressing the

Temperature (^)

. The first time the key
is pressed the newest code will be displayed. Each
additional key press shows the next code. Once all the
codes have been displayed a “d” is displayed and the
process repeats. If there are no Diagnostic Codes
available, “00” will be displayed for the Diagnostic Code.

There will be no multiple occurrences of either a
diagnostic code or help code generated in the same
cycle reported on the list. But if the same code occurs in
repeated cycles, it will be registered.

Clearing Diagnostic Codes

To clear the diagnostic code list press

Air Fluff and Wrinkle Release - 13 Key
or

Air Fluff

and

Wrinkle Release

- 15 Key

for 3 seconds while in diagnostic mode.

Diagnostic Codes

Code Description Trigger Action Taken

Dryer Thermistor

1

Short Sensed

The
thermistor
resistance is
very low,
with a
temperature
> 175
degrees.

Check for:

-

Clogged lint
screen.

-

Restricted
vent system.

Failed thermistor.

Code Description Trigger Action Taken

Thermistor Open

2

Sensed

Door Circuit

3

Failure

Possible motor

4

transistor error

Not Used

5

Non Volatile

6

Memory

Stuck Key A key is

8

The
thermistor
resistance is
very high

Invalid state
for more
than 256
milliseconds
If either
motor
transistor is
seen open or
shorted
during
startup

Problem
Detected
with integrity
of
parameters
stored in
EEPROM
memory.

sensed to be
pressed
more than
75 seconds,
the key shall
be assumed
to be stuck.

Check for:

-

-

Loose or open wire

Check for:

- Loose or open wire
terminals in Door

Sense circuit.

Check for:

-

-

-

If relay does not

function, replace

machine control

Run membrane pad

check and replace

console w/membrane

pad if necessary.

Low ambient
temperature in
room (Below
50oF/10oC).
Outside vent
damper is stuck
open in
wintertime.

terminals

Loose
connections in
motor circuit.
Run System
Check Mode
and check the
motor relay
function.
If relay
functions,

diagnostic
code.

board.

Disregard

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Section 9. Dryer Controls Overview

© 2000 Maytag Appliances Sales Company

9-13

MDE/MDG6800, MDG5500

Ribbon

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Membrane Pad Continuity Checks

Unplug connector and touch probe of meter to the

Note:

appropriate pin numbers. Meter will show infinity on
open keys and continuity on closed keys.

Membrane

Pad

Sensor dry J7(12) J7(13)
Time dry J7(11) J7(13)
Time(^) 13 Key
Time(+) 15 Key
Time(v) 13 Key
Time(-) 15 Key
Temperature (^) 13 Key
Dry Temp(^) 15 Key
Dry Temp (v) 15 Key J7(10) J7(14)
Sensor Dry Level 13
Key
Very Dry (<) 15 Key
Damp Dry (>) 15 Key J7(19) J7(14)
Wrinkle Release J7(11) J7(15)
Wrinkle Prevent J7(9) J7(15)
Air Fluff J7(10) J7(15)
Start/Pause J7(11) J7(16)
Signal(v) 13 Key
Signal(-) 15 Key
Off J7(9) J7(16)
Signal(^) 13 Key
Signal(+) 15 Key

J7 Connector

Pin Number Pin Number

J7(10) J7(13)

J7(9) J7(13)

J7(11) J7(14)

J7(12) J7(14)

J7(12) J7(15)

J7(12) J7(16)

Harness

P1

J3

BB1 BB2

J4

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Pin No. 1

Description Connector

Heater Relay Internal
Output
LI Board (input) BB1(1) BB2(3) 120VAC Door must be closed.
Motor
(input)
Neutral (input) BB2(2) BB1(1) 120VAC
Door Sense BB2(3) BB1(1) 120VAC Door must be open
Thermistor J4(1) J4(2) 5VDC NTC

Sensor Bar J4(3) J4(4) 24VDC

Pin Num
P1 BB1(1) 120VAC

BB1(2) BB2(3) 120VAC Door must be closed

© 2000 Maytag Appliances Sales Company

Connector
Pin Num

Voltage Comments

70 F = 10K ohms
150 F = 1754 ohms

Section 9. Dryer Controls Overview

9-14

MDE/MDG7500, MDE/MDG9800

No

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Service Mode

This mode provides Service Personnel the ability to
verify the operation of the dryer.

The Service Mode can be implemented in the middle of
any dry cycle. While in the Service Mode, the
Technician can start special diagnostic tests such as a
System Check Mode, Membrane Pad Check, Display
Software version number and display diagnostic/help
code listings.

Removing A Favorite Cycle

If the consumer wants a favorite cycle removed, see
below:

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time dry

create a

favorite

sensor dry

(no heat)

edit a

favorite

Air fluf

favoritesmore cycles

delete a

favorite

© 2000 Maytag Appliances Sales Company

blue jeans towels

bl

Enter Service Mode:

Press Help and Back Keys for 3 seconds or until a
beep is heard.

Exit Service Mode

Press the
exit Service Mode. After 5 minutes of inactivity in
Service Mode, the machine will exit Service Mode and
return to the state just prior to where the user first
entered Service Mode.

Yes

key or Exit Service Mode on the display

OFF

Section 9. Dryer Controls Overview

return without

making changes

Making changes

9-15

MDE/MDG7500, MDE/MDG9800

cancel cycle

Output Status

sensor circuit enabled

press PAUSE and select output below

16023110

User Interface

Enter User Interface and follow the directions on screen.
This test will check the Membrane Pads and Touch
Screen. The Membrane Pad and Touch Screen Test
must be completed in approximately 10 seconds or a
failure will be shown on the display.

Membrane Pad Test

After passing the Touch Screen Test a Membrane Test
will be performed.

This will check the Membrane Switch and display the
status of the Touch Screen Test that was just
performed. The user will be prompted to press the
following 5 membrane switches in any order” (i.e. home,

favorites, back, help

off

(i.e.

) should not be pressed. Pressing the

and

start/pause

). The sixth key

off

key will
shut down the machine. If all keys are pressed,
“Membrane switch test passed” will be displayed. If any
key(s) are not pressed within 5 seconds, the user will be
prompted to “Touch the key(s) that are not highlighted”.
If key(s) again are not pressed within 5 seconds, the
display will show which key(s) failed.

System Check Cycle Not Running

System checks can be performed whether the dryer is
in a dry cycle or not. If the dryer

is not

in a dry cycle, the
display screen will allow the technician to toggle various
components On/Off. The screen will also display the
current status of the component inputs to the control
board.

toggle motor

toggle heater (if
motor is running)

toggle sensor

circuit

exit system

check

System Check Cycle Running

If the dryer is already running a cycle and the system
check is activated, then the screen will display the
status of all the outputs and inputs to the control board.

cancel cycle: This will stop the current cycle.
exit system check:

This will exit the system check
screen and revert back to the previous screen shown on
the display panel.

To toggle outputs,

motor on

heat on

Input Status

damp dry sensed

normal dry sensed

short circuit sensed

door closed

drum temperature

ambient temperature

exit system

check

Diagnostic/Help Codes

Displays all the diagnostic codes and how many cycles
ago the codes occurred.

Displays all the help codes and how many cycles ago
the codes occurred.

Displays the current software version.

Displays the cycle count.

Enter Service Mode by Pressing

Help

and

Back

Keys

for 3 seconds or until a beep is heard.

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Section 9. Dryer Controls Overview

© 2000 Maytag Appliances Sales Company

9-16

MDE/MDG7500, MDE/MDG9800

disregard the

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exit diagnostic/

help codes

Diagnostic Codes

Code Description Trigger Action Taken

Dryer Thermistor

1

Short Sensed

Thermistor Open

2

Sensed

Door Circuit

3

Failure

Possible motor

4

transistor error

Not Used

5

Non Volatile

6

Memory

The
thermistor
resistance is
very low,
with a
temperature
> 175
degrees.
The
thermistor
resistance is
very high

Invalid state
for more
than 256
milliseconds
If either
motor
transistor is
seen open or
shorted
during
startup

Problem
Detected
with integrity
of
parameters
stored in
EEPROM
memory.

cycle count

xxxx

clear

help codes

Check for:

-

Clogged lint
screen.

-

Restricted
vent system.

Failed thermistor.

Check for:

-

Low ambient
temperature in
room (Below
50oF/10oC).

-

Outside vent
damper is stuck
open in
wintertime.

Loose or open wire

terminals

Check for:

- Loose or open wire
terminals in Door

Sense circuit.

Check for:

-

Loose
connections in
motor circuit.

-

Run System
Check Mode
and check the
motor relay
function.

-

If relay
functions,

diagnostic

code.
If relay does not
function, replace
machine control

board.

Disregard

Code Description Trigger Action Taken

Stuck Key A key is

8

sensed to be
pressed
more than
75 seconds,
the key shall
be assumed
to be stuck.

Run membrane pad

check and replace

console w/membrane

pad if necessary.

Membrane Pad Continuity Checks

Note:

Unplug connector and touch probe of meter to the
appropriate pin numbers. Meter will show infinity on
open keys and continuity on closed keys.

Membrane

Pin Number Pin Number

Pad

Home J7(3) J7(5)
Favorites J7(4) J7(5)
Back J7(3) J7(6)
Start/Pause J7(4) J7(7)
Off J7(3) J7(7)
Help J7(4) J7(6)

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Section 9. Dryer Controls Overview

© 2000 Maytag Appliances Sales Company

9-17

MDE/MDG7500, MDE/MDG9800

16023110

Description Connector

Heater Relay Internal
Output
LI Board (input) BB1(1) BB2(3) 120VAC Door must be closed.
Motor
(input)
Neutral (input) BB2(2) BB1(1) 120VAC
Door Sense BB2(3) BB1(1) 120VAC Door must be open
Thermistor J4(1) J4(2) 5VDC NTC

Sensor Bar J4(3) J4(4) 24VDC

Pin Num
P1 BB1(1) 120VAC

BB1(2) BB2(3) 120VAC Door must be closed

Connector
Pin Num

Voltage Comments

70 F = 10K ohms
150 F = 1754 ohms

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Section 9. Dryer Controls Overview

© 2000 Maytag Appliances Sales Company

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Section 10. Wiring Diagrams

10-27

MDG6800

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Section 10. Wiring Diagrams

10-28

MDE9800

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Section 10. Wiring Diagrams

10-29