Preventive Maintenance and Fault-finding
8.5.7.8 No RF Output (Voyager II and AVP3000 only)
8.5.7.8.1 Configuration
There are a number of possible reasons why a unit might not produce an RF output.
The output must be turned on to enable the L-band or IF output, and (depending on
the Output Power-up State setting) these actions may have to be repeated after a
power outage.
If a transport stream has been successfully created and can be monitored on the
front panel confidence monitor, check for these satellite modulator settings:
• Output Select must be set to IF or L-band as required (Modulation Parameters
menu).
• Output State must be On (Line-up menu).
• The transport stream must be set to Online.
8.5.7.8.2 Error Conditions
The satellite modulator option includes a number of internal health monitoring
features that can turn off the RF outputs. The purpose of these features is to prevent
the unit from outputting a bad signal that would interfere with the service of other
users of the satellite. If a fault is detected that would result in an output signal that is
outside the expected frequency band, then the RF output is turned off and an alarm
is generated. You cannot prevent these alarms from turning off the RF output, but
you can determine how they are reported on the user interface. Masking these
alarms does not stop the RF outputs being turned off.
The effects of alarms that can turn off the RF outputs are shown in the table below.
Table 8.7 Effect of Alarms That Can Turn Off RF Outputs
Alarm Name IF output turned off? L-band output turned off?
OCXO Fault Yes Yes
Clock PLL Unlocked Yes Yes
L-band Carrier Frequency Unlocked No Yes
If one of these alarms is present, then powering the unit down, waiting for at least 10
seconds and then re-powering the unit might recover it to normal operation,
depending on the alarm’s cause. Don’t forget that you may need to enable the
output after the power cycle.
If power cycling does restore operation after a persistent alarm, we still recommend
that you return the unit for service at the next convenient opportunity
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