3.4 MAINTENANCE PROCEDURES
Due to the sensitivity of some components (especially the MOS components) and their
susceptibility to damage by static discharge, maintenance will be limited to changeover in the
case of
and replacement of telephone parts in the case of stations. To protect faulty
assemblies, and items such as Stations, Handsfree Consoles, RTIU, Power Supply, and the
Main Equipment; all transport must take place in the protective containers supplied with the
new item. For return of faulty
and other items of equipment refer to section 3.7 Repair
Procedures.
3.4.1
Stations
Maintenance on stations will be confined to replacement of transmitter and receiver inserts,
cords, plugs and sockets. Faults in the
within the station, or with the pushbutton
assemblies will be rectified by replacement of the station complete.
3.4.2
Power Supplies
The power supplies associated with the 1236 and 2260 systems are separate items from the
main equipment. When they are diagnosed as being faulty, they will be changed over complete.
Note:
The power supply for the 67 6 system is built info the main equipment. When the
power supply is faulty for this system, it will necessitate changeover of the entire
main equipment. The
from the faulty main equipment will need to be re-installed
in the new main equipment. This is necessary to ensure that system programming
and abbreviated
memories are not lost.
*CAUTION*
The power supplies are powered from the 240 Volt mains supply and hazardous voltages are
present within. Do not attempt to repair these units.
3.4.3
Remote Extension and Tie Line Interface Unit
The Remote Extension and Tie Line Interface Unit
will be maintained similarly to the
main equipment, i.e. individual
will be replaced when they are diagnosed to be faulty.
When the
power supply is diagnosed to be faulty, it will necessitate changeover of the
complete. The
in the faulty
will need to be re-installed in the new RTIU.
3.4.4
Other Items
When other items of equipment are diagnosed as faulty by the flow charts or testing, they will be
changed over complete.
This includes Direct Select Station
Handsfree Console
Call Metering Unit
and the Ring Generator Unit
etc.
3.4.5
Printed Board Assemblies
Any fault in the PBA will necessitate replacement of the whole assembly. No repair of
will
be done on site or in field depots. Any attempt to repair a PBA in the field may damage the PBA
resulting in additional faults.
Coded board ejectors are provided on
to facilitate their removal from the main equipment.
The board ejectors are coded into two categories.
RED EJECTORS: Boards with red ejectors must not be removed from the main equipment
until the mains power is turned OFF.
(ii)
WHITE EJECTORS: Boards with white ejectors may be removed from the system at any
time.
In addition to the above categories, boards containing MOS circuitry are marked with a RED
LINE on the edge of the board and/or a “MOS” sticker on the ejector.
As previously mentioned, the boards require careful handling and, in general, must NOT be
removed whilst the power is still on.
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