Ericsson AVP 4000, Справочное руководство, Страница: 329 / 422

Preventive Maintenance and Fault-finding
1/1553-FGC 101 1790 Uen Y 8-9
•
Loss of audio (from any source).
• Loss of VBI data.
•
Invalid parameter (indicating which area video/audio/VBI/ANC data).
•
Critical alarm (card has malfunctioned, internal log holds nature of failure).
• Over temperature (including a warning level as well as a critical level).
All masking of alarms is handled by the Host Card.
Self-monitoring
The VCM self-monitors for correct operation and correct any inconsistencies it finds.
This includes the resetting of malfunctioning sub-systems or the whole card if
necessary. The module attempts to maintain correct operation to minimize the
effects of faults. All such actions are reported through the alarms/status/logging
back to the Host Card.
Module Responses
The Host Card monitors all responses back from the module and resets the module
if appropriate. This includes initiating redundancy switches if this results in limiting
the error period. All actions are logged by the Host Card.
8.5 Fault-finding
8.5.1 Fault-finding Philosophy
It is the objective of this section to provide sufficient information to enable you to
rectify apparent faults or else to identify the suspect module, where possible. Some
basic procedures are provided to follow in the event of a suspected failure. It is
assumed that fault-finding has already been performed at a system level and that
other equipment units have been eliminated as the possible cause of the failure.
Warning!
Do not remove the top cover of this equipment. Hazardous voltages are present
within this equipment and may be exposed if the top cover is removed. Only
Ericsson trained and approved service engineers are permitted to service this
equipment.