Sea Tel DAC-03, Installation And Operation Manual

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DAC-03 Tracking Antenna Controller Maintenance & Troubleshooting
7-1
7. Maintenance & Troubleshooting
Below are the common adjustments, maintenance and troubleshooting that may be required in the lifetime of your
system. Also refer to the Maintenance & Troubleshooting section of your Antenna Pedestal manual.
7.1. General Cautions & Warnings
CAUTION - Electrical Shock Potentials exist on the Gyro
Compass output lines. Assure that the Gyro Compass output is
turned OFF when handling and connecting wiring to the Terminal
Mounting Strip or the boards inside the ACU.
CAUTION
- Allow only an
authorized dealer
to install or service your
Sea Tel System components. Unauthorized installation or service can be
dangerous and can invalidate the warranty.
7.2. Troubleshooting The ACU
The following paragraphs list the problems you might encounter when performing the functional checkout
steps in the previous section of this manual. Following the problems are suggestions of where to start
looking to solve the problem. Refer to the Drawings section of this manual and in the Antenna manual for
any/all pertinent block diagrams, schematics, wiring diagrams and assembly drawings to aid in diagnosing
any type of failure.
Try pressing RESET first and then in some cases you may want to turn Power OFF for a short period of time
then turn the ACU back ON to see if that restores normal operation. Remember, with most Gyro Compass
types you MUST enter the beginning Heading value EVERY time you power-up the ACU, before you will be
able to retarget your desired satellite.
Verify that the SETUP PARAMETERS are set correctly (refer to the Setup section of this manual).
7.2.1. Display is blank
This indicates no power to the internal electronics. Assure that the front panel Power switch is ON.
Check the AC line voltage, Power Cord and internal power supply fuses. Check the cables on the
rear panel of the ACU to assure they are properly connected. One at a time disconnect (and check
display status) the cables plugged into J11 M&C, then J13 NMEA, then J3 Gyro Compass to see if
one of these cables is shorting the ACU Power. Call your dealer to report this failure and arrange for
repair service.
7.2.2. Power-up displays “REMOTE NOT RESPONDING”
This indicates a problem in the Antenna Control cable or communications modems in the ACU
and/or Antenna PCU. Check the Antenna Control Cable connections at the J1 “Antenna” jack on the
rear of the ACU and at the antenna pedestal inside the radome. Verify the RS422 signal levels and
connections. Refer to drawing 116040 "Unlimited Azimuth Interconnect Diagram" at the end of
this manual. Repair any faulty connections at the ACU or PCU to their respective multiplexer.
Using a spectrum analyzer observe the 1.1 and 1.5 MHz Pedestal M&C carrier signals on the RX IF
cable. Hold the RESET key down and observe the 1.5 MHz signal is at a steady high frequency of
1.525 MHz. Release the RESET key and the signal should occasionally be seen switching to 1.475
MHz. This indicates the Base Multiplexer is transmitting to the PCU. If the Base Multiplexer is not
transmitting, replace it. If the Base Multiplexer is still not transmitting, replace the ACU Main PCB.