Test #1: Acu Power Check - Whirlpool WFW3090GW Service Manual

TESTING COMPONENT
Electrical Shock Hazard
Only authorized technicians should perform
TEST PROCEDURES
diagnostic voltage measurements.
After performing voltage measurements,
IMPORTANT: The following procedures
disconnect power before servicing.
may require the use of needle probes
Failure to follow these instructions can result in
to measure voltage. Failure to use needle death or electrical shock.
probes will damage the connectors. To
ease the process of measuring voltage
Component Testing
and resistance, test points for each pin are
TESTING WASHER COMPONENTS FROM THE
accessible through the slots in the plastic
CONTROL
beneath each ACU connector.
Before testing any of the components, perform the following
checks:

TEST #1: ACU Power Check

• The most common cause for mis-diagnosed control
failure is poor connections. Therefore, disconnecting,
inspecting and reconnecting wires will be necessary
This test checks for incoming and outgoing power
throughout test procedures.
to and from Appliance Control Unit (ACU). This test
• All tests/checks should be made with a VOM or DVM
assumes that proper voltage is present at the outlet. having a sensitivity of 20,000 ohms-per-volt DC, or
greater.
1. Unplug washer or disconnect power.
• Check all connections before replacing components,
looking for broken or loose wires, failed terminals, or
2. Gently lay washer on its right side
wires not pressed into connectors far enough.
• IMPORTANT: Voltage checks must be made with all
to access the ACU.
connectors attached to the boards.
3. Visually check that all connections to the
• Resistance checks must be made with power cord
unplugged or power disconnected, and with wiring
interference filter (IF) are securely connected.
harness or connectors disconnected from the control.
See Figure 2, below.
The testing procedures in this section may require the use
of needle probes to measure voltage. Failure to use needle
4. Visually check that all connections to the
probes may damage the connectors.
ACU are fully inserted. See Figure 3, below.
IMPORTANT: Whenever the washer is tilted for service or
troubleshooting, drain water from the basket and remove any
5. If both visual checks pass, go to step 6.
load items in the basket.
INTERFERENCE FILTER (IF) - FIGURE 1
Filter Output - Line (BU)
Filter Output - Line (BU)
Filter Input - Power Cord Line (BK)
Filter Input - Power Cord Line (BK)
Figure 2 - Interference Filter (IF)
3-4 Whirlpool Compact Front Load Washer
n
WV-DP
J15-Inlet Valve
1
For Service Technician Use Only
DANGER
FOR SERVICE TECHNICIAN'S USE ONLY
TEST #1: ACU Power Check
This test checks for incoming and outgoing power to and from
Appliance Control Unit (ACU). This test assumes that proper
voltage is present at the outlet.
1. Unplug washer or disconnect power.
2. Gently lay washer on its right side to access the ACU.
3. Visually check that all connections to the interference
filter (IF) are securely connected. See Figure 1, page 3-4.
4. Visually check that all connections to the ACU are fully
6. Plug in washer or reconnect power.
inserted. See Figure 2, page 3-5.
7. With a voltmeter set to AC, check for line
5. If both visual checks pass, go to step 6.
voltage at the input of the interference filter. 6. Plug in washer or reconnect power.
7. With a voltmeter set to AC, check for line voltage at the
See Figure 2.
input of the interference filter. See Figure 1, page 3-4.
If line voltage is present, go to step 8.
¾ If line voltage is present, go to step 8.
¾ If line voltage is not present, verify the continuity of
If line voltage is not present, verify the
the power cord. If it fails the continuity check, replace
the power cord.
continuity of the power cord. If it fails the
8. With a voltmeter set to AC, check for line voltage at the
continuity check, replace the power cord.
output of the interference filter. See Figure 1, page 3-4.
¾ If line voltage is present, go to step 9.
8. With a voltmeter set to AC, check for line
¾ If line voltage is not present, replace the interference
voltage at the output of the interference filter.
filter.
See Figure 2.
9. With a voltmeter set to AC, check for input line voltage to
the ACU across pins 1 and 2 of connector J42 AC Input (IF).
If line voltage is present, go to step 9.
See Figure 2, page 3-5.
¾ If line voltage is present, go to step 10.
If line voltage is not present, replace the
¾ If line voltage is not present, check harnesses and
interference filter.
connections between the filter and the ACU. Visually
inspect inside connector housing for bent or damaged
9. With a voltmeter set to AC, check for input
terminals. Repair as necessary.
line voltage to the ACU across pins 1 and 2
10. Check UI input voltage:
Verify that there is 5V between pin 10 and 12 at J21.
of connector J42 AC Input (IF). See Figure 3.
¾ If there is 5V, go to step 11.
If line voltage is present, go to step 10.
¾ If there is not 5V, disconnect J21 and check for 15V
between pin 9 and pin 12. If there is not 15V, replace
If line voltage is not present, check
the ACU.
harnesses and connections between the
11. Unplug washer or disconnect power.
12. Reassemble all parts and panels.
filter and the ACU. Visually inspect inside
13. Perform the Service Test Cycle on pages 2-4 and 2-5 to
connector housing for bent or damaged
verify repairs.
terminals. Repair as necessary.
Filter Output - Neutral (BU)
Filter Output - Neutral (BU)
Filter Input - Power Cord Neutral (WT)
Filter Input - Power Cord Neutral (WT)
SB-PRS-UI
J21-User
12