Dexter Laundry T-900 Operator's Manual page 37

Intermediate CPU board,
speed #1 Ribbon Cable
works, but no Input/Output
high speed PCB
#2
(continued)
Machine Variable
tumbles in Frequency Drive
only one
direction
CPU Board,
Ribbon Cable, or
input/output
board
Excessive Mounting System
vibration
Drive Belt
Pulleys
Under loading
Hot or Cold Water Valves
water does
not enter the
tub
Fill Hose or Water
Valve screens
Water
Pressure Switch
Hose
Pressure Switch
CPU board,
Ribbon Cable
Input/Output PCB
8514-244-001 REV PR page 37
Check input/output PCB for illuminated red speed 1 #15 and high speed 2
#16 output lights. If no red output lights illuminated, check single red light
on CPU. Single red light should be illuminated. If light is flashing or not
on, remove power from washer for 2 minutes to reset board. Reapply
power to washer and check red CPU light. If on solid, CPU okay. If still
flashing or not on, replace CPU. If CPU tests okay, change Ribbon Cables
between CPU and input/output PCB. (Check with factory for latest testing
procedures for I/O PCB.) If red intermediate and high extract output lights
on input/output board are illuminated, check to ensure that 0VDC is going
from the Input/Output PCB to the variable frequency drive. If no voltage,
replace I/O PCB.
Check blue and orange wires on variable frequency drive for alternating
0V to 24 VDC for forward and reverse direction from the Input/Output
PCB. If no voltage, see CPU board, Ribbon Cable or Input/Output PCB
below. Be sure to check wire connections at drive.
Check Input/Output PCB for alternating or Input/Output PCB red output
lights for forward #13 and reverse #14. If no red output lights
illuminated, check single red light on CPU board. Single red light should be
illuminated. If light is flashing or not on, remove power from washer for 2
minutes to reset board. Reapply power to washer and check red CPU light.
If on solid, CPU okay. If still flashing or not on, replace CPU board. If CPU
tests okay, change Ribbon Cables between CPU and Input/Output PCB. If
red forward #13 and reverse #14 output lights on the Input/Output PCB
are illuminated, check to ensure that 0VDC is going from the Input/Output
PCB to the variable frequency drive (only when the lights are on). When
lights are off, check to ensure that 24VDC is going from the Input/Output
PCB to the variable frequency drive. If neither voltage is correct, replace
I/O PCB.
Check these areas:
• Strength of mounting structure, concrete or base.
• Mounting bolts may be loose and need tightening.
Worn drive belt can cause vibration and noise.
Check for damaged pulleys.
Wash recommended load size as specified for washer model (in lb/kg).
Small loads contribute to out of balance loading and increase vibration.
Check to ensure that water valve is operating. If not, check for 120VAC to
water valve from Input/Output PCB. If 120VAC, change water valve. If no
voltage, check Input/Output PCB as described below.
Check water inlet screens for blockage and clean if necessary.
Check to ensure that water is turned on and operating.
Check hose for holes. Be sure the inlet end of the large part of the hose is
lower than the rest of the hose and is free of debris.
Pressure switch must be in the empty position to close the circuit to the
Input/Output PCB. The green Empty light #14 on the Input/Output PCB
must be lighted. Check pressure switch for continuity across terminals #31
& #22 indicating pressure switch has reset to empty.
Check Input/Output PCB for illuminated red water or Input/Output PCB
valve output light. If no red output light #5 (for Hot) or #7 (for Cold)
illuminated, check single red light on CPU board. Single red light should be
illuminated. If light is flashing or not on, remove power from washer for 2
minutes to reset board. Reapply power to washer and check red CPU light.
If on solid, CPU okay. If still flashing or not on, replace CPU board. If CPU
tests okay, change Ribbon Cables between CPU and Input/Output PCB. If
red water valve output light #5 (for Hot) or #7 (for Cold) on input/output
PCB is illuminated, check to ensure that 120VAC is going from the
Input/Output PCB to the water valve. If no voltage, replace I/O PCB.