Comtech EF Data KST-12000 - Manual (Page 106)

KST-12000 Ku-Band Satellite Terminal Revision 4
Maintenance MN/KST12000.IOM
Table 6-2. Test Points
Test Point Description
TP3 12.5V input power voltage.
TP6 Down converter AGC voltage (0 to 4V).
TP7 Up converter attenuator voltage (0 to 4V).
TP8 HPA AGC voltage (0 to 4V).
TP9 Up converter AGC voltage (0 to 4V).
6.2 Fault Isolation
Once the terminal has been set up for operation, troubleshooting faults can be
accomplished by monitoring the terminal faults either remotely or via the optional front
panel/keypad and display.
System faults are reported in the FAULT menu.
The following list should be used in isolating a problem and deciding the appropriate
action to be taken. Refer to Figures 6-1 and 6-2 for the locations of the various modules
mentioned in this list.
Fault Possible Problem and Action
+5 VOLT +5V power supply fault. Indicates the +5V power supply on the M&C
board is at a high or a low voltage condition. Allowable level variation is
± 5%. Check for a short on the +5V line or faulty connection at P3 on the
M&C.
+12 VOLT +12V supply fault. Indicates the +12V supply is at a high or low voltage
condition. Check for a short on the +12V line or faulty connections
between any of the internal modules.
HPA High Power Amplifier fault. Check for a loose connector at P12, then
replace the high-power amplifier. The high-power amplifier is not intended
to be opened in the field. Once the problem has been isolated, the
transmitter must be turned back ON.
LNA Low Noise Amplifier fault. Check the RF cable to the LNA, then replace
the LNA.
U/C LOCK
U/C LO V
t
-S TUN
U/C LO V
t
-V TUN
Up Converter Lock fault. Check for loose connections at P7, P8, and P4.
Also check all RF coaxial connectors on the U/C synthesizer and U/C
board before replacing modules. Once the problem has been isolated, the
transmitter must be turned back ON.
D/C LOCK
D/C LO V
t
-V TUN
Down converter tuning fault. Check for loose connections at P10, P11,
and P4. Also check all RF coaxial connectors on the D/C synthesizer and
D/C before replacing the modules. Once the problem has been corrected,
the transmitter must be turned back ON.
IF LOCK IF Lock fault. Check for loose connections at P9 and P4. Also, check all
RF coaxial connectors on the IF LO module. If all connections are good,
replace the IF LO module. Once the problem has been isolated, the
transmitter must be turned back ON.
IF TUN IF Tuning fault. Check for loose connections at P9 and P4. Also check all
RF coaxial connectors on the IF LO module. If all connections are good,
replace the IF LO module. Once the problem has been isolated, the
transmitter must be turned back ON.
6–2