advertisement
27” Gas Dryer ⎯Technical Information
MDG9700A *
• 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 16025911 for detailed installation, operating, testing, troubleshooting, and disassembly instructions.
!
CAUTION
All safety information must be followed as provided in Service Manual 16025911.
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power before servicing, unless testing requires power.
Model MDG9700A*
Power Source
Voltage AC 120VAC
Motor Horsepower
Cabinet Dimensions
1/3
Height 38”
Width 27”
Depth 30.75”
Features
Cycles 16
Controls LED
Air Fluff X
Wrinkle Release
Wrinkle Prevent
X
X
Tumbler Stainless
End of Cycle Chime X
Drum Light
Freshen Up Cycle
Drying Rack
X
X
X
Weight lbs.
Uncrated 138
©2005 Maytag Services
Troubleshooting
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power before servicing, unless testing requires power.
Will Not Run
Will not start or run:
• All wires are hooked up to their corresponding terminals.
• Dryer is plugged in.
• Blown fuse or circuit breaker.
• Door switch functional...door closed. Check for error code 3 (See Table for code definition).
• Start/Pause rotary selector dial functional.
• Control Board operational.
• Drive motor functional.
• Check motor winding resistance: 2.88ohms between pin #3 and 4, 3.5ohms between pin #4 and 5.
Will Not Dry Gas Models
Poor Gas Ignition
When the dryer is operated on a heat setting, the igniter should be energized and burner shall fire within 45 seconds at 120 VAC. The failure of a component in this system will usually be indicated by one of three symptoms:
The igniter does not glow. If the igniter does not heat up, remove power and using an ohmmeter, check the following:
• Open flame sensor
• Shorted booster coil
Motor runs/ tumbler will not turn:
• Belt off or broken/damaged.
• Idler tension spring too weak or stretched.
• Idler pulley jammed or stuck.
Runs a few minutes and then stops:
• Lint buildup around drive motor.
• Low voltage present.
• Blower impeller blocked in blower
• housing.
• Drive motor - start switch contacts stuck closed.
Blows fuses or trips circuit breaker:
• The amperage readings are at 240 volts. One line will be 24 amps and the other line will be 21 amps. The neutral line will be at 3 amps. If the above amperages are present, then the house wiring, fuse box or circuit breaker should be suspect.
• Shorted heating element to housing.
• Incorrect wiring or a wire shorting to ground.
• Drive motor winding shorting to ground.
Gas Models
• During ignition the dryer will draw X amps. With the burner ON, the dryer will draw X amps. If the dryer is drawing amperages above this, then the house wiring, fuse box or circuit breaker is suspected to be at fault.
• Igniter harness loose and shorted to base.
• Incorrect wiring or wire shorted to ground.
• Drive motor winding shorting to ground.
Will Not Dry
Will not heat (motor runs):
• Open heating element.
• Hi-Limit trips easily or is open.
• Regulating thermostat trips easily or is open.
• Membrane switch open.
• Check Thermistor.
• Bad motor switch (Neutral supply)
• No power from control (L1 supply)
Igniter glows - No gas ignition. If the igniter heats up but the main burner flame is not ignited, remove power and using an ohmmeter, check the following:
• Open secondary coil
• Open holding coil
• Open wire harness
• Stuck flame sensor (Stuck closed)
The gas is ignited but the flame goes out. If a normal ignition takes place and after a short while the flame goes out, check for the following:
• Radiant sensor contacts opening
prematurely.
• Weak gas valve coil may open when stressed by higher temperatures.
• Bad drum seals
Improper drying/clothes wrinkled/ rough texture/long dry time:
• Lint filter is not clean.
• Restriction in exhaust.
• Outside exhaust hood damper door stuck closed.
• Exhaust too long, too many elbows, flex ductwork installed.
• Poor intake air available for the dryer.
• Incorrect tumbler speed. Tumbler belt slipping.
• Blower impeller bound; check for foreign material in blower area.
• Customer overloading dryer.
• Check clothing labels for fabric content and cycle selected.
• Clothes too wet due to insufficient spin out by washer.
©2005 Maytag Services
Troubleshooting
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power before servicing, unless testing requires power.
Will Not Shut Off
• Check Membrane Pad.
• Check Electronic Control Board.
• Short in sensor circuit.
Troubleshooting the electronic control circuit:
• Check for miswiring of the electrical connector at the electronic control board.
Noisy and/Or Vibration
• Thumping Check for loose tumbler baffle, rear tumbler roller(s) worn or misaligned, out-ofround tumbler or high weld seam on tumbler.
• Ticking Check for loose wire harness or object caught in blower wheel area.
• Scraping Check for front or rear bulkhead felt seal out of position or worn tumbler front bearings.
• Roaring
Check for blower wheel rubbing on blower housing or bad motor bearings.
• Popping or squealing sound
.
Check for a sticky or frayed belt.
Service Mode
This mode provides Service Personnel the ability to verify the operation of the dryer.
The Service Mode can be implemented at any time, including the middle of a dry cycle. While in the Service
Mode, the Technician can start special diagnostic tests such as a System Check Mode, LED Switch/Check,
Display Software version number and display diagnostic/help code listings.
Enter Service Mode:
Dryer must be on before Service Mode can be entered.
Press Chime and Temperature Keys for 3 seconds, or until 3 beeps are heard. The machine will now be in
Service Mode. Upon entry into Service Mode, the Sensor
Bar Touch Data is to be displayed.
Exit Service Mode
Press the OFF key to exit Service Mode or repeat the
Chime and Temperature sequence.
Diagnostic Tests
The following table lists the various tests available while in the Service Mode. Before advancing to the next test, the current test running must be terminated.
Press the following keys to access:
Key Press
Wrinkle Prevent
Displays “d”
Special Test/Function
Display list of diagnostic codes.
To sequence thru the diagnostic and help codes.
Then rotate the Cycle
Selector Knob
Temperature Key
Start/Pause
Display software revision number
Start or pause cycle running but remain in diagnostic mode. Display the number of cycles ago the diagnostic code occurred.
System Check Mode
While in Service Mode, pressing the
Time and Wrinkle Prevent keys for 3 seconds, will put the dryer into the System Check mode and "in" will display. The following table lists the various functions based on the keys being pressed.
System Check Mode Table
Key Pressed:
Start/Pause rotary selector dial
Rotate the Cycle Selector
Knob to Delicates
Rotate the Cycle Selector
Knob to Sensor
Dry
Rotate the Cycle Selector
Knob to Wrinkle Control
Function
Performed
Cycles the motor on/off.
LED’s and 7 segment display flash.
View current cycle temperature in Celsius.
Rotate the Cycle Selector
Knob to Time Dry
Segment display is “1” for sensor bar short, “0” for sensor bar open
View current cycle temperature in
Fahrenheit.
©2005 Maytag Services
Troubleshooting
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power before servicing, unless testing requires power.
LED/Switch Check
While in Service Mode, pressing the Chime and Wrinkle
Prevent keys for 3 seconds, will start a LED/Switch Test.
While a diagnostic code is displayed, if the Start/Pause button in the center of the Rotary Cycle Selector is pressed and held, the machine will display the number of cycles ago the diagnostic code occurred. When the
To exit the test at any point, press the same keys again for 3 seconds or press the OFF key to exit Service
Mode.
Start/Pause button is released, the diagnostic code is again displayed.
Perform the check by pressing the keys which toggle the
LED’s on and off.
All switch pads must be pressed within 5 minutes for this test to pass. PA will be displayed for five (5) seconds once all switch pads have been pressed and this test is completed. Following 10 seconds of inactivity at any point, the test will exit without any display. The
Power
Off
switch pad must be pressed twice within thirty (30) seconds to cancel this test.
Switch Action
Wrinkle Prevent Press once
Code Description Trigger Action
1
2
Dryer
Thermistor
Short Sensed
Thermistor
Open Sensed
The
Thermistor resistance is very low.
The
Thermistor resistance is very high
Check for:
- Clogged lint screen.
- Restricted vent system.
- Check Thermistor resistance.
Check for:
Low ambient temperature in room (Below
Adjust Time
Time
Temperature
Dryness Level
Selector Knob
Start Pause
Press once
Press four times
Press three times
Press four times
Rotate 1 position
Press once
Clearing Diagnostic Codes
To clear the diagnostic code list press the
Sensor Dry
Level
and
Time
keypads together for 3 seconds while viewing the list. The cycle count for each diagnostic code will be reset to 0, but not the machine cycle count.
Diagnostic Codes
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.
Access Diagnostic Codes by entering the Service Mode and pressing Wrinkle Prevent. A d will be displayed.
Rotate the Cycle Selector Knob in either direction to step through the list of codes one code at a time. Once an initial direction is selected by the user (either Clockwise or Counterclockwise), subsequent movements of the knob in the same direction will show older codes. If the user changes direction and turns the knob in the opposite direction, the more recent code will be displayed.
3
4
Door Circuit
Failure
Possible motor transistor error
Invalid state for more than 256 milliseconds
If either motor transistor is seen open or shorted during startup
-22
°
F/-30
°
C).
- Outside vent damper is stuck open in wintertime.
- Loose or open wire terminals.
- Check Thermistor resistance.
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, disregard the diagnostic code.
- If relay does not function, replace machine control board.
©2005 Maytag Services
Troubleshooting
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power before servicing, unless testing requires power.
Code Description Trigger Action
8
10
Stuck Key A key is sensed to be pressed more than
75 seconds, the key shall be assumed to be stuck.
No Wet Clothes Sensor bar detects no wet clothes while a
Sensor Dry
Cycle
Display Fault/Error Codes
Disp Description tS Dryer
Thermistor
Short Sensed
Trigger
The Thermistor resistance is very low.
Run membrane pad check and replace console w/membrane pad if necessary.
Check for:
- Running dryer with no wet clothes in sensor dry cycle do
FE dC hE
Door Open
Power source frequency error
Door Circuit
Failure
Heater Error
Running the dryer with door open
Invalid power source frequency
Invalid state for more than 256 milliseconds
Invalid heating temperature in running the dryer
Action Taken
Check for:
- Clogged lint screen.
- Restricted vent
system.
- Check Thermistor
resistance.
- Check for diagnostic code 1
Check for:
- Close the door, and run the dryer
- Loose or open wire terminals in
Door Sense circuit.
- Check for diagnostic code 3
Check for:
- Not using regular power source frequency
- Invalid power frequency sense circuit
Check for:
- Loose or open wire terminals in
Door Sense circuit.
- Check for diagnostic code 3
Check for:
- Restricted vent system.
- Check Thermistor resistance.
©2005 Maytag Services
Component Testing
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power before servicing, unless testing requires power.
Illustration Component
Thermistor Unplug harness connector and test from wire insertion side.
Pin #2 and Pin #6 of CN6
Results
10k ohms @ 77F NTC
Door Switch
Light
Belt Switch
Motor
TH1 Thermostat
85 C/185 F 25A
Unplug connectors and test switch terminals.
Door open terminals COM to NC/ 1 to 3
Door open terminals COM to NO/1 to 2
Door closed terminals COM to NC/ 1 to 3
Door closed terminals COM to NO/ 1 to 2
Unplug connectors and test switch terminals.
Check across terminals
Unplug connectors and test switch terminals.
Check across terminals switch closed
Check across terminals switch open
Unplug harness connector and test motor circuits.
Pin #4 and Pin #5 (Windings)
Pin #1 and Pin #2 (Centrifugal switch)
Unplug connectors and test Thermostat terminals.
Check across terminals
Infinity
Less than 1 ohm
Infinity
Less than 1 ohm
80 to 100 ohms
Less than 1 ohm
Infinity
2 ohms
Open
Less than 1 ohm
Heater Element
Sensor Bars
Radiant Sensor
Unplug connectors and test Heater terminals
Unplug harness connector and test from wire insertion side.
Pin #4 to Pin # 5 of CN6
Unplug connectors and test sensor terminals.
10 ohms
Infinity (Dry load)
190 ohms
±
10% (Wet load)
Closed
©2005 Maytag Services
Gas Valve
Component Testing
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power before servicing, unless testing requires power.
Illustration Component
TH2 Thermostatt
230F/110C
Unplug connectors and test Thermostat terminals.
Results
Less than 1 ohm
Gas Valve Unplug connectors and test valve terminals.
Check across terminals #1 and #3
(Booster Coil).
Check across terminals #1 and #2
(Holding Coil).
Check across terminals #2 and #3 (Both coils in series).
Check across terminals #4 and #5
(Secondary Coil).
550 ohms
1350 ohms
1900 ohms
1300 ohms
Motor Contacts
Function 1M
Start
Run
2M
= Contact closed
3M 5M 6M
Centrifugal Switch (Motor)
123
45
©2005 Maytag Services
Wiring Diagram
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power before servicing, unless testing requires power.
©2005 Maytag Services
advertisement
Related manuals
advertisement