Comtech EF Data SDM-100A - Manual (Page 66)

Operation SDM-100A Satellite Modem
3–32 Rev. 0
3.2.1.3.5 Common Equipment Faults
Fault/Alarm Possible Problem and Action
Battery/Clock M&C battery voltage or clock fault. Indicates a low voltage in the memory
battery.
Typically will be active when a modem has been Hard Reset, or the
firmware has been changed. When a Hard Reset has been executed or
the firmware has been changed, this fault will typically be active when the
modem is first turned on. It should clear automatically as the battery
charges up.
-12 Volt Supply -12V power supply fault. Indicates a high or low voltage condition. Level is
± 5%.
Check for a short on the -12V line from the power supply or on the board.
Check TP2 on the M&C section to verify the proper -12V monitor voltage
(1.06V). If this voltage is not correct, it will verify that the -12V supply is not
at the proper level. This would indicate the power supply is faulted. Return
modem for repair.
+12 Volt Supply +12V power supply fault.
Use the same procedure as with -12V fault. To verify the +12V power
supply voltage, check TP4 on the M&C. A voltage of 3.81V will be
monitored when the +12V is at the proper level.
+5 Volt Supply +5V power supply fault.
Use the same procedure as with -12V fault. To verify the +5V power
supply voltage, check TP5 on the M&C section. A voltage of 2.5V will be
monitored when the +5V is at the proper level.
Controller Controller fault. Indicates loss of power in the M&C card.
Typically indicates the controller has gone through a power on-off cycle.
Interface Module Interface module fault. Indicates a problem in programming the interface.
This could indicate a problem in the M&C or in the interface between the
interface section and M&C. Return the modem for repair.