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6.
Troubleshooting Guide
This chapter is a brief guide of what to check if the unit fails to function normally.
It also describes the built in testing and diagnostic routines of the ALS board.
6.1
ALS Diagnostics
The ALS board has two main diagnostic features. The first is the group of four red
lights on the ALS board. The second is the self test mode.
The lights are numbered L1 to L4 and behave as follows:
L1 – flashes whenever the ALS program is running
L2 – changes state whenever a valid score is received from the APS
L3 – changes state whenever a valid poll is received from the front desk.
L4 – changes state whenever a key is pressed.
When the ALS is powered up, it will perform various tests while the
Testing
Wait
… message is displayed. If it encounters any errors, it will stop processing.
Approximately 20 seconds later it will attempt to restart again.
The ALS board also has a self test mode. When in this mode the program will test
various parts of the hardware and display the results. The ALS board will go into
this mode if switch 8 on dip switch S1 is closed on the ALS board, or due to a
command from the
Lane Control System
.
The tests performed are:
-
RAM test. All system ram is tested. The amount or RAM reported may be
slightly below the amount installed in the motherboard due to some being used
for shadowing ROMS.
-
CMOS test. The battery backed CMOS RAM on the ALS board is tested.
-
Timer Test. The timer should count down 5 seconds.
-
Switch Display. The position of each dip switch on the ALS board is
displayed.
-
ROM test. The software is contained in ROM, and each group of ROMs has a
checksum to determine if its contents have been corrupted. If a ROM or group
of ROMS fails this test they should be replaced.
-
CMOS checksum display. The displayed checksum represents the contents of
the battery backed RAM. This contents should not change if the unit is
switched off then on again (still in test mode, s1-8 closed). If it does change,
then either the CMOS ram is faulty, or the backup battery on the ALS board is
flat. This battery will charge while power is connected to the board.
