2.5 BOARD INSTALLATION INSTRUCTIONS
Before inserting boards into the ME rack, the following preliminary work is required.
*WARNINGS*
A.
This equipment contains a considerable number of MOS, and other static sensitive
components. To reduce the incidence of the premature failure due to static discharge, the
following precautions MUST be taken:
Always ensure that power is disconnected before plugging
Always discharge static from yourself by touching a conductive part of the main
equipment before handling boards.
Handle
by the edge or by the handles. Do not handle PBA tracks, components
or edge connectors (contaminants introduced by fingers can cause corrosion and
high resistance connections).
Components are physically delicate. Finger pressure on a component can fracture,
but not necessarily break component leads: a future fault.
To protect against physical damage and damage due to static discharge,
must
ALWAYS be wrapped in aluminium foil (e.g. cooking foil) and inserted into an
ANTI-STATIC plastic bag and placed in the protective container provided with the new
item. In the case of the ECMB remove the battery and package separately.
These procedures apply equally to both working and faulty
Careless handling,
storage and transporting will cause secondary or future faults.
B.
To prevent the likelihood of damage to electronic components, power should be switched
off before working on the systems.
C.
The cabling between the main equipment and stations is polarity sensitive. It is essential
that the correct polarity be maintained from the main equipment to the
pairs
must not be swapped. Care must be exercised when checking voltages on cabling. Do not
short or bridge between terminals as this will cause fuses on the ESTB boards to blow.
WIRE
603 PLUG/
WIRE
COLOUR
610 SOCKET
DESIGNATION
WT White
AL1
A-pair
BL Blue
AL2
RD Red
1
B D + B - p a i r
BK Black
5
D.
Power supplies are powered from the 240 volt mains supply and hazardous voltages are
present within. Do not attempt to repair these devices.
E.
ECMB-
D BOARDS
If these
are replaced, all site dependant data and abbreviated dial numbers are
lost. It will be necessary to re-programme the system.
The battery may be changed by removal of the daughter board, BTB-A, (without loss
of any programmed data) while the ECMB power is on.
The press button
must be pressed to reset the crosspoints of the system after
replacing ESTB or ELNB boards when the power is on.
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ISSUE 2