Maytag MDB series User Manual

TESTING
Maytag Chopper Dishwashers
n
3-13
For Service Technician Use Only
Drain Motor
This test will check the wiring to the drain motor and the drain
motor itself. The following items are part of the drain motor
circuit.
n Harness/Connecon
n Drain Motor
n Control Board
Test Procedure
1. Verify that drain hose or drain path is not obstructed.
Check for blockage from sump check valve to customer’s
plumbing. Check for plugged garbage disposal or disposal
plug not knocked out. Check drain loop, stuck check valve,
or for plugged hoses. Repair as needed.
2. Check the drain motor and electrical connecons by
performing the Service Diagnosc Cycle. The following
steps assume that this step was unsuccessful.
Strip Circuit – Drain Motor
3. Are all the loads controlled by TRIACs not working?
¾ YES – check for open door switch, TRIAC fuse, or pilot
relay.
¾ NO – just the drain motor. Go to step 4.
4. Unplug dishwasher or disconnect power.
5. Remove outer door panel to access control board.
6. Unplug connector P6 from control board.
7. Check the drain motor—using an ohmmeter, measure the
resistance between P6-1 and P6-3.
¾ If the resistance is between 15-60 ohms, the drain
motor and harness are good. Go to step 8.
¾ If outside the range, replace the drain motor.
¾ If an open circuit is detected, check connecons and
harness connuity between control and drain motor. If
good, replace the drain motor.
8. Reconnect P6 to control board.
9. Set voltmeter to AC and connect leads to test-pads P10-
1 & P6-1 on the control board. Plug in dishwasher or
reconnect power.
10. Start the Diagnosc Cycle and at the proper interval
measure for AC out of the control between P10-1 & P6-1.
(Refer to Drain Motor Strip Circuit below.)
IMPORTANT: The Drain Motor must be connected to the
control board to measure voltage accurately!!!
¾ If no AC voltage is measured, replace the control board
and retest.
¾ If 120 VAC is measured and drain motor is running, go
to step 11.
11. Unplug dishwasher or disconnect power.
12. Reassemble all parts and panels.
13. Plug in dishwasher or reconnect power and run Diagnosc
Cycle to verify repair.
DANGER
Electrical Shock Hazard
Only authorized technicians should perform
diagnostic voltage measurements.
After performing voltage measurements,
disconnect power before servicing.
Failure to follow these instructions can result in
death or electrical shock.
5
Fill
Drain
Dispenser (Detergent and Rinse Aid)
Water Softener
L1
BK
P4-2 P6-4
P10-1
P6-6
P6-7
P6-9
P4-1
Use top hole of jumper
W2 as test point for F9.
N.O.
K2
Pilot L1 Relay
(Also see Door
Switch Circuit)
Fuse
F9
Electronic Control
Electronic Control
Float
(In normal position,
holds switch closed)
BR
BR
N.O.
Pin 3Pin 1
Overfill
Float Switch
No test pad on P6-4.
Recommend using test pad on P10-1.
No test pad on P6-7.
Recommend using test pad on P6-6.
Electronic Control
Float Switch
Input
BR
BR
Pin 3Pin 1
Triac
Fill Valve
890 Ω - 1,00 Ω
120V, 60 Hz, 6W
WH
N
L1
BK
P4-2
P6-3
P10-1
P6-1
P4-1
BR BR WH
N
Use top hole of jumper
W2 as test point for F9.
N.O.
K2
Pilot L1 Relay
(Also see Door
Switch Circuit)
Fuse
F9
Electronic Control
Electronic Control
No test pad on P6-3.
Recommend using test pad on P10-1.
Pin 1
Pin 3
Drain Motor
15 Ω -  Ω
120V, 60 Hz, W
Triac
N
P4-1
Pin 1
Pin 3
N.O.
K2
P4-2 P9-3 P9-1
BK
L1
V
V
P10-1
Fuse
F9
1.4K Ω - .K Ω
120V, 60 Hz, 10W
Pin 1
Pin 5
Tr iac
Electronic Control
Use top hole of jumper
W2 as test point for F9.
Pilot L1 Relay
(!lso see Door
Switch Circuit)
Te
st pad on P9-3 might crowd P9-1
Recomme
nd using test pad on P10-1.
Dispenser Solenoid
260W - 300W
120V, 60Hz, 17W
Electronic Control
WH
Dispenser Wax Motor
L1
Regeneration Valve
BK
P4-2
P7-3
P10-1
P7-1
P4-1
N
WH
BUBU
Use top hole of jumper
W2 as test point for F9.
K2
Pilot L1 Relay
(Also see Door
Switch Circuit)
Fuse
F9
Pin 1
Pin 3
N.O.
Electronic Control
Electronic Control
Triac
No test pad on P7-3.
Recommend using test pad on P10-1.
Regeneration Valve
890
Ω - 1,090 Ω
120V, 60 Hz, 6W
Electronic Control
P11-2
P11-1
(RD)
N.O.
N.O.
5V
(Optional Flowmeter)
Sensor
Input
(Closed when salt low)
Salt Level Reed Switch
39 K Ω
Salt Level Sensing
Pin 1
Pin 1
Pin 4
Pin 2
Pin 3
Pin 3
Electronic Control
(RD)
RD
RD

Maytag MDB series Specifications

General

Type	Built-In
Capacity	14 Place Settings
Tub Material	Stainless Steel
Energy Star Certified	Yes
Soil Sensor	Yes
Heated Dry	Yes
Control Type	Electronic
Delay Start	Yes