Toa EXES-6000, Operating And Troubleshooting

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This chapter deals with how to find in the field
the defective card in the system already
installed, according to symptoms of defect.
Now that the field repair is limited to the
replacement of the card, it is not referred to
how to repair the defective card at the compo-
nent level.
Each symptom is given on conditions that
power supply and stations work normally and
that the following are properly arranged:
Initial programming setup
CP unit's DIP switch setting
Mounting of each card on its designated
location in a cabinet rack
Wirings
In order to find whether or not the station is
faulty, it is recommended to replace the
original station with normal one to see if the
same symptom will result. "XX unit is faulty"
that appears in the flow chart means the type
of card that is the most suspicious for the
cause. If replacing the card still does not
remedy the symptom, try to find the other
suspicious card by following the signal flow
from the input through reference to the fore-
going sections of this booklet. This also applies
to the other symptoms not mentioned in this
troubleshooting.
Symptom 1. Cannot dial.
* The dial data transmitted from the station
finally comes into the CP unit's input port
through the dial data bus line of the LM unit.
The data bus consists of 8 lines, which are
connected to the input ports No. 0 through No.
7, respectively. Each bus line corresponds to
the station numbers that skip every 8 num-
bers; for example, the input port No. 0 corres-
ponds to the stations No. 200, No. 208, No.
216 .... and the input port No. 1 to the stations
No. 201, No. 209, No. 217 and so on. There-
fore, when dialing is impossible from a certain
station, whether or not the CP unit is faulty can
be determined by dialing from stations of
which numbers increase or decrease by every
8 from the faulty station number.
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VIII. TROUBLESHOOTING