Nautel NG1000, Troubleshooting Manual

Page: 31 / 164

NG1000 Troubleshooting Manual Responding to alarms
Issue 0.4 2010-10-12 Page 1-9
Sys Con +5V Fault CONTROLLER This alarm occurs when the system controller’s +5 V
power supply’s output voltage is outside the
acceptable range of 4.7 V to 5.3 V. Suspect a possible
fault with the +5 V supply circuitry on the system
controller PWB (A1). To replace a system controller
PWB, see
“System Controller PWB Replacement” on
page 1-23 .
Sys Con +12V Fault CONTROLLER This alarm occurs when the system controller’s +12 V
power supply’s output voltage is outside the
acceptable range of 11.2 V to 12.8 V. Suspect a
possible fault with the +12 V supply circuitry on the
system controller PWB (A1). To replace a system
controller PWB, see
“System Controller PWB
Replacement” on page 1-23 .
System Fwd Pwr Low CONTROLLER This alarm occurs when the system’s RF output power
falls below the preset low power tone threshold
(configurable betweeen 25 and 75%). Check the
active transmitter for associated faults.
System High VSWR CONTROLLER This alarm occurs when the VSWR at the system’s RF
output exceeds 5.5:1. The transmitter system is
inhibited.
Sys Interlock Open EXTERNAL This alarm occurs when the external interlock circuit
for the overall system is not closed, inhibiting the
transmitter’s output. Check the interlock connection
between J1-1 and J1-2 on the system controller PWB.
If the interlock is intact, check all external interlock
switches. Otherwise, suspect a problem with the
interlock circuitry on the system controller PWB.
System Reset N/A This alarm occurs when a system reset is in progress.
Alarm (with Prefix) Alarm/Status LED Description and Troubleshooting Action