Test Procedures - Maytag MHW9000YW0 Mode D'emploi

FOR SERVICE TECHNICIAN'S USE ONLY

TEST PROCEDURES

IMPORTANT: The following procedures may
require the use of needle probes to measure
voltage. Failure to use needle probes will
damage the connectors. To ease the process
of measuring voltage and resistance, test points
for each pin are accessible through the slots
in the plastic beneath each CCU connector.
TEST #1: CCU Power Check
This test checks for incoming and outgoing power
to and from Central Control Unit (CCU). This test
assumes that proper voltage is present at the outlet.
1. Unplug washer or disconnect power.
2. Remove top panel to access the
machine electronics.
3. Visually check that all connections to the
interference filter (IF) are securely connected.
See Figure 10, below.
4. Visually check that all connections to the
CCU (Figure 11) and Expansion Board (EB)
(Figure 15, page 21) are fully inserted.
Filter Output - Line (PK)
Filter Input - Power Cord Line (BK)
Figure 10 - Interference Filter (IF)
DI6-Detergent Dispenser Motor
FM3-Flow Meter
DCS3-Door Closed Switch
Locking Tab
PS8-Pressure Sensor
SET2-Temperature
Sensor
UIP3-Expansion
Brd Power
UI7-User Interface
MI3-MCU
Communications
FAC3-Data
to Expansion Brd
Figure 11 - Central Control Unit (CCU)
DO NOT REMOVE OR
DL3-Door Lock Coil
DESTROY
5. If both visual checks pass, go to step 6.
6. Plug in washer or reconnect power.
7. With a voltmeter set to AC, check for line
voltage at the input of the interference filter.
See Figure 10.
 If line voltage is present, go to step 8.
 If line voltage is not present, verify the
continuity of the power cord. If it fails the
continuity check, replace the power cord.
8. With a voltmeter set to AC, check for line
voltage at the output of the interference filter.
 If line voltage is present, go to step 9.
 If line voltage is not present, replace the
interference filter.
9. With a voltmeter set to AC, check for input
line voltage to the CCU across pins 1 and 2 of
connector IF2. See Figure 11.
 If line voltage is present, go to step 10.
 If line voltage is not present, check
harnesses and connections between the
filter and the CCU. Repair as necessary.
Filter Output - Neutral (PK)
Filter Input - Power Cord Neutral (WT)
DP2-Drain Pump
RP2-Vent Fan
VCH7-Hot/Cold Valves
VSF2-Steam Valve
MS2-MCU Power
IF2-Interference
Filter
DLS2-Door
Lock Switch
HE2-Heater
Element
HSG2-Expansion
Board
•
= pin-1
PAGE 13