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Troubleshooting
© Copyright, Alliance Laundry Systems LLC – DO NOT COPY or TRANSMIT
Network Board Service
Commonly Used Abbreviations:
FEC - Front-End Control – the Dryer/Tumbler
Control, Top-Load Washer Control, Front-Load
Washer Control, and Washer/Extractor Control are all
referred to simply as the Front-End Control through-
out this document
NWB – Network Board
NIB – Network Interface Board
LED – Light Emitting Diode
Network Board LED
When the operation of the Network Board is suspect,
the state of the LED may be examined to determine
whether the Network Board is operating properly.
Network Board Operating LED Test
LED is Flashing One Second On / One Second Off -
This is what the LED should be doing in normal
operation. If the LED is following this sequence, the
processor on the board is executing the code correctly.
However, there may still be other problems with the
board.
LED is Constantly Off -
If the LED is constantly off,
there is probably no power to the NWB. There must be
24VAC across pins 6 & 7 on header H1 for the NWB
to operate. If there is 24VAC across pins 6 & 7 and the
LED is a constant off, the NWB will need to be
replaced.
LED is Flashing Rapidly or is Constantly On -
If
the LED is constantly on or is flashing rapidly or
erratically, the NWB may be in a lock-up state or may
be bad. Remove power from the board by pulling
header H1, and then put the header back again. If the
LED begins to flash one second on / one second off, the
board is probably OK. If this does not happen, the
NWB will need to be replaced.
LED Flashes Rapidly 3 Times -
This sequence
indicates the beginning or end of a communication
sequence with the FEC. The service personnel may
determine if the NWB is communicating with the FEC
by following the procedure in the following section.
Network Board Communicating LED
Test
Test of Communications Between FEC and NWB
Using LED -
Power down the NWB by disconnecting
header H1. Re-connect H1. Approximately 15
seconds after H1 is reconnected
(7 LED flashes), the LED should flash rapidly 3 times,
indicating that it is beginning communication with the
FEC. Two LED flashes later, the LED should flash
rapidly 3 times again, indicating the end of a successful
communication sequence. If this does not occur, the
NWB is not communicating with the FEC.
Once it has been determined that the processor on the
NWB is correctly executing the NWB code, the service
personnel may now check for the following other
possible malfunctions of the NWB (and/or the FEC).
• NWB is not communicating with the FEC
• NWB is not allowing the Card Reader to
communicate with the FEC
• NWB is not communicating with the PC
Network Board to Front-End Control
Communication Problems
NWB will not Communicate with FEC -
If the NWB
is not communicating with the FEC, the NWB, FEC, or
Harness may be at fault. For the following cases, use
the Network Board Communicating LED test
previously described to test the communication link
between the FEC and the NWB using the LED.
The FEC must supply 5 VDC to the NWB via pins 1 &
2 on H1 for the NWB to function correctly. If the
5VDC is not present, the NWB can in no way
communicate with the FEC. If this voltage is not
present, the harness or the FEC may be at fault.
If there is 5VDC across pins 1 & 2 of H1 and the NWB
will not communicate with the FEC, swap the harness
between the FEC and NWB with an known good
harness. If this fixes the problem, the harness is at
fault.
If the harness is not at fault, the NWB should be
swapped with a known good board. If this fixes the
problem, the NWB needs to be replaced. If after
changing out the NWB and the harness with known
good samples the NWB will not communicate with the
FEC, the FEC must be at fault.
In general, there are three possible sources of failure,
the NWB, the FEC, and the Harness. Parts may need
to be swapped out individually to isolate the problem.
