ST950S Plus+ Installation and Commissioning Manual
10.3.9. Faults with Handset
If the handset does not operate correctly when plugged into the handset port on Main CPU Card, do
the following:
•
Check that the H5V supply fuse (F1) on the CPU Card is intact.
•
Check that there is a +5V supply on pins 9 and 10 of the handset socket (0V is on pins 1, 7, 18
and 19). With the handset plugged in check the ripple voltage on 5V supply.
•
(This supply powers those handsets that do not have their own supplies.)
•
To fully investigate, this supply may require the use of an oscilloscope.
•
Switch off controller and withdraw Main CPU Card. Check security of ICs mounted in sockets of
the above card. If no loose ICs are found, replace Main CPU Card.
•
Replace Main CPU Card and re-check to see if handset now operates correctly.
10.3.10. Intermittent Faults/Problem Sites
If a site has an intermittent fault or a fault which keeps repeating, then first the appropriate procedure
for the fault should be followed as most paths have more than one suggested area to check for the
fault.
If the fault is still intermittent, do the following:
•
Gently - try and move/flex each card whilst in situ to check for any intermittent connections.
•
If any intermittent connections are found, replace appropriate card.
•
Gently move cables and wiring looms to check for any intermittent connections.
•
Switch controller ‘off’ and withdraw all cards. Check security of any ICs mounted in sockets on
the CPU Card.
•
Re-fit cards and re-check operation of controller.
10.4. Replacement of Cabinet Mounted Cards
This section covers removal and fitting of cards in the ST950 Plus
+
cabinet. Also described are
procedures to ensure that the card functions correctly when fitted.
10.4.1. Safety Requirements
DANGER:
Before replacing any fuses, cards etc., IT IS ESSENTIAL THAT THE POWER TO THE
CONTROLLER IS ISOLATED.
Failure to isolate the supply before changing parts may result in damage to the Controller.
The exception will be 48VDC PSU, if paired with redundancy units, as these are designed to
be hot pluggable.
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