Download Print this page
Nautel NX100 Troubleshooting Manual
Hide thumbs Also See for NX100:

Advertisement

NX100 Troubleshooting Manual
Section 1:
This section provides instructions you need when performing troubleshooting on the NX100
transmitter. This section includes the following topics:
Corrective maintenance
Electrostatic protection - see page 1-3
Identifying an alarm - see page 1-4
Responding to alarms - see page 1-20
Troubleshooting RF power modules - see page 1-29
Other
Module Replacement Procedures - see page 1-19
If none of the procedures and alarms described in this section address your problem, contact Nautel
for assistance.
Corrective maintenance
Corrective maintenance procedures consist of identifying and correcting defects or deficiencies that
arise during transmitter operation. Local and/or remote alarm signals are generated when a
malfunction occurs. If an alarm condition is caused by a malfunction in the RF power stage, the
transmitter may maintain operation at a reduced RF output level. The nature of the fault – and station
policy – will dictate whether an immediate maintenance response is necessary. Fault analysis and
rectification may be conducted from three different levels, with a different technical competence level
required for each: on-air troubleshooting, remote or local, and off-air troubleshooting.
CAUTION:
The transmitter contains many solid state devices that may be damaged if
subjected to excessive heat or high voltage transients. Every effort must be taken
to ensure that circuits are not overdriven or disconnected from their loads while
turned on.
On-air troubleshooting
On-air troubleshooting can be performed from a remote location, or locally at the transmitter site.
Issue 3.2 2016-02-08
Responding to alarms
Responding to alarms
Page 1-1

Advertisement

loading

Summary of Contents for Nautel NX100

  • Page 1 • Other Module Replacement Procedures - see page 1-19 If none of the procedures and alarms described in this section address your problem, contact Nautel for assistance. Corrective maintenance Corrective maintenance procedures consist of identifying and correcting defects or deficiencies that arise during transmitter operation.
  • Page 2 NX100 Troubleshooting Manual Responding to alarms Remote troubleshooting Remote on-air troubleshooting consists of monitoring the transmitter's radiated signal using an on-air monitor, and observing the status of each remote fault alarm indicator. Information obtained from these sources should enable an operator to decide whether an alarm response may be deferred to a more convenient time, an immediate corrective action must be taken, or if a standby transmitter must be enabled (if one is available).
  • Page 3 NX100 Troubleshooting Manual Responding to alarms Electrostatic protection The transmitter's assemblies contain semiconductor devices that are susceptible to damage from electrostatic discharge. The following precautions must be observed when handling an assembly which contains these devices. CAUTION: Electrostatic energy is produced when two insulating materials are rubbed together.
  • Page 4 NX100 Troubleshooting Manual Responding to alarms Identifying an alarm The best way to identify an alarm is by viewing the front panel’s Transmitter Status page (Figure 1.1). If an alarm exists, the Status button at the bottom of the AUI display will be red. Press or click the Status button to go to the Transmitter Status page.
  • Page 5 Responding to alarms 4. If the troubleshooting and subsequent replacement of a suspect PWB or RF power module does not remove the fault condition, contact Nautel. NOTE: Before undertaking any troubleshooting, record all AUI meter readings and note if any other alarms are displayed on the Transmitter Status page .
  • Page 6 NX100 Troubleshooting Manual Responding to alarms Page 1-6 Issue 3.2 2016-02-08...
  • Page 7 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-7...
  • Page 8 NX100 Troubleshooting Manual Responding to alarms RF Off Reset RF Off Reset RF Off Reset Page 1-8 Issue 3.2 2016-02-08...
  • Page 9 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-9...
  • Page 10 NX100 Troubleshooting Manual Responding to alarms Page 1-10 Issue 3.2 2016-02-08...
  • Page 11 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-11...
  • Page 12 NX100 Troubleshooting Manual Responding to alarms Page 1-12 Issue 3.2 2016-02-08...
  • Page 13 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-13...
  • Page 14 NX100 Troubleshooting Manual Responding to alarms Page 1-14 Issue 3.2 2016-02-08...
  • Page 15 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-15...
  • Page 16 NX100 Troubleshooting Manual Responding to alarms Page 1-16 Issue 3.2 2016-02-08...
  • Page 17 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-17...
  • Page 18 NX100 Troubleshooting Manual Responding to alarms Page 1-18 Issue 3.2 2016-02-08...
  • Page 19 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-19...
  • Page 20 NX100 Troubleshooting Manual Responding to alarms Responding to alarms Controller: External PDM Inhibit The external PDM inhibit is wired to the control/interface PWB. A Controller: External PDM Inhibit alarm indicates that an external PDM inhibit command is present. The alarm could be caused by an short circuit in the external wiring path to the control/ interface PWB or a fault in the switching circuitry on the control/interface PWB.
  • Page 21 NX100 Troubleshooting Manual Responding to alarms 5. If 15 V is present on J6-5 and J6-1, the external interlock circuit is open (normally caused by an open interlock switch). Module faults There are many alarms on the AUI, prefixed by the text Module , that indicate faults related to one or more of the 2040 RF power modules in a cabinet.
  • Page 22 NX100 Troubleshooting Manual Responding to alarms RF power module troubleshooting Refer to “Removing and reinstalling RF power modules” on page 1-24 for removal and installation instructions and then refer to “Troubleshooting RF power modules” on page 1-29 for detailed troubleshooting information.
  • Page 23 Recovery from this alarm is automatic when the ac voltage rises to an acceptable level. NOTE: An NX100 transmitter has only one rack (or cabinet) and will only display Rack 1. If the transmitter does not automatically recover from this alarm, the low ac voltage is normally caused by low ac mains voltage or improper primary taps on the power transformer.
  • Page 24 NX100 Troubleshooting Manual Responding to alarms Removing and reinstalling RF power modules Removing an RF power module 1. Confirm the location of the RF power module that is being removed. Note the alarm text includes a Module serial address that is also identified on the front panel of each RF power module.
  • Page 25 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-25...
  • Page 26 RF power module is enabled. You should hear a relay in the back of the transmitter pick up (energize). 5. Upgrade the subsystem software using the AUI’s Upgrade Software page under the System Settings menu. See the NX100 Operations and Maintenance Manual for detailed instructions. Page 1-26 Issue 3.2 2016-02-08...
  • Page 27 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-27...
  • Page 28 NX100 Troubleshooting Manual Responding to alarms Page 1-28 Issue 3.2 2016-02-08...
  • Page 29 • A soldering iron and desoldering tool. • An NX100 spares kit (contains replacement semi-conductors). Electrostatic Precautions The RF power module contains semiconductor devices that are susceptible to damage from electrostatic discharge. Be sure to follow the electrostatic precautions in “Electrostatic protection”...
  • Page 30 2. If the diode is not satisfactory, replace the it by desoldering its surface-mount leads and case from the PWB. Locate a replacement diode (Nautel Part # QM54) in the spares kit, if purchased, and solder it to the PWB, noting correct orientation.
  • Page 31 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-31...
  • Page 32 5. Ensure the surface of the chassis/heat sink is clean and free of debris. 6. Obtain a replacement MOSFET (Nautel Part # QR6868) and a new thermal pad (Nautel Part # HAK55) from the spares kit, if purchased, and install them on the RF power module chassis using the two M4 screws removed in step 3.
  • Page 33 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-33...
  • Page 34 6. Apply a thin film of thermal compound to the heatsink. 7. Obtain a replacement MOSFET (Nautel Part # QR75) from the spares kit, if purchased, and install it on the heat sink using the alignment post on the heat sink as an installation aid.
  • Page 35 NX100 Troubleshooting Manual Responding to alarms Control/exciter panel board removal/replacement The control/exciter panel (A11, see Figure 1.6) contains the control/interface PWB (A11A1), two digital AM exciter PWBs [A (A11A2) and B (A11A3)], remote interface PWB (A11A4), optional GPS sync PWB (A11A5) and optional Exgine PWB (A11A7). The control/interface PWB physically interconnects with both digital AM exciter PWBs and the remote interface PWB.
  • Page 36 NX100 Troubleshooting Manual Responding to alarms Remote interface PWB replacement 1. Remove and retain six sets of mounting hardware from the remote interface PWB (A11A4). 2. Pull the remote interface PWB away from the control/interface PWB (A11A1). It may be helpful to gently pry the connector loose with a screwdriver.
  • Page 37 NX100 Troubleshooting Manual Responding to alarms Issue 3.2 2016-02-08 Page 1-37...
  • Page 38 In this case, repeat Step 2 through Step 6 for the operational exciter’s digital AM exciter PWB. If there is no operational exciter, contact Nautel for the required calibration data. Page 1-38 Issue 3.2 2016-02-08...
  • Page 39 NX100 Troubleshooting Manual Responding to alarms 8. Remove and retain four sets of mounting hardware from the digital AM exciter PWB being replaced (A11A1 or A11A2). 9. Pull the digital AM exciter PWB away from the control/interface PWB (A11A1). It may be helpful to gently pry the connector loose with a screwdriver.
  • Page 40 16. On the front panel AUI, reset any active alarms. 17. Upgrade the subsystem software using the AUI’s Upgrade Software page under the System Settings menu. See the NX100 Operations and Maintenance Manual for detailed instructions. 18. Set the transmitter to its RF On state.
  • Page 41 7. Remove and retain 13 sets of mounting hardware from the control/interface PWB (A11A1). 8. Obtain a replacement control/interface PWB (Nautel Part # NAPC160B/01). 9. Set the COMB CONT INTLK (E1) and REMOTE SUPPLY (E3) jumpers on the replacement PWB to the same positions as the defective PWB.
  • Page 42 Step 14. Upgrade the subsystem software using the AUI’s Upgrade Software page under the System Settings menu. See the NX100 Operations and Maintenance Manual for detailed instructions. GPS Sync PWB replacement 1. Remove and retain four sets of mounting hardware from the GPS sync PWB being replaced (A11A5).
  • Page 43 NX100 Troubleshooting Manual Responding to alarms PDM Drive Distribution PWB replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off the power at the source and verify the 2040 bright green LEDs on the power module interface PWBs - in the back of each cabinet - are off before removing any connections or PWBs.
  • Page 44 NX100 Troubleshooting Manual Responding to alarms RF drive distribution PWB replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off the power at the source and wait until the 2040 bright green LEDs on the power module interface PWBs - in the back of each cabinet - are off before removing any connections or PWBs.
  • Page 45 PWB. 4. Carefully remove and retain six sets of mounting hardware. 5. Remove the rack interface PWB from the transmitter. 6. Obtain a replacement rack interface PWB (Nautel Part # NAPI152A) and set DIP switch S1 as follows. S1 Position A15 Setting Issue 3.2 2016-02-08...
  • Page 46 Reconnect each RF power module’s PDM cable; the LED sequence should change to flashing amber. 10. Upgrade the subsystem software using the AUI’s Upgrade Software page under the System Settings menu. See the NX100 Operations and Maintenance Manual for detailed instructions. Page 1-46 Issue 3.2 2016-02-08...
  • Page 47 NX100 Troubleshooting Manual Responding to alarms SCR Rectifier Inspection/Replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off the power at the source and wait until the 2040 bright green LEDs on the power module interface PWBs - in the back of each cabinet - are off before removing any connections or assemblies.
  • Page 48 NX100 Troubleshooting Manual Responding to alarms 2. If you are responding to a Rectifier Fan 1 (or 2) Fail alarm (if not, proceed to Step 3), inspect the SCR rectifier assembly’s cooling fans (see Figure 1.14 on page 1-47) for debris that might restrict proper movement of the fan blades.
  • Page 49 NX100 Troubleshooting Manual Responding to alarms Low Voltage Power Supply Replacement WARNING: Lethal voltages exist inside the transmitter when the power is turned on. Turn off the power at the source and wait until the 2040 bright green LEDs on the power module interface PWBs - in the back of each cabinet - are off before removing any connections or assemblies.
  • Page 50 NX100 Troubleshooting Manual Responding to alarms 4. Remove the power supply module from the transmitter, noting its reference designation (U3 through U7) should be marked on the side panel near the module. 5. Reverse Step 1 through Step 4 to reinstall the new power supply module. Reconnect all wiring.
  • Page 51 NX100 Troubleshooting Manual Responding to alarms RF Power Module Fan Tray replacement Figure 1.16. Issue 3.2 2016-02-08 Page 1-51...
  • Page 52 NX100 Troubleshooting Manual Responding to alarms 1. Open the front door. 2. Determine the suspect fan tray assembly (A35A60 through A39A64) associated with the offending RF power module # alarm(s). 3. Remove and save two sets of mounting hardware. Pull the fan tray assembly out of the transmitter.