Nautel GV40 Programming manual

4: TROUBLESHOOTING MANUAL
GV40/GV30
TRANSMITTER
Document ID: NHB-GV30-GV40-TRB
Version: 4.0
Issue Date: 2018-02-26
Status: Standard
Making Digital Radio Work

VERSION 4.0 2018-02-26 PAGE III
GV40/GV30 TROUBLESHOOTING MANUAL
Contact Information
Nautel Limited
10089 Peggy’s Cove Road
Hackett’s Cove, NS Canada B3Z 3J4
Toll Free: +1.877.6NAUTEL (662.8835)
(Canada & USA only) or
Phone: [phone] or
Fax: [phone]
Nautel Inc.
201 Target Industrial Circle
Bangor, Maine USA 04401
Phone: [phone]
Fax: [phone]
Customer Service (24-hour support)
+1.877.628.8353 (Canada & USA only)
+1.902.823.5100 (International)
Email: [email protected]
Web: www.nautel.com
The comparisons and other information provided in this document have
been prepared in good faith based on publicly available information.
For verification of materials, the reader is encouraged to consult the
respective manufacturer's most recent publication on the official
website or through contact with Customer Service.
© Copyright 2018 NAUTEL. All rights reserved.

GV40/GV30 TROUBLESHOOTING MANUAL TABLE OF CONTENTS
VERSION 4.0 2018-02-26 PAGE 4.V
CONTENTS
Contact Information iii
RELEASE CONTROL RECORD vii
Responding to alarms 1-1
Corrective Maintenance 1-1
Electrostatic Protection 1-3
Identifying an Alarm 1-4
Accessing the Inside of the Transmitter 1-32
Troubleshooting Tips 1-33
Replacement Procedures 1-43
RF Power Module Replacement 1-44
Troubleshooting RF Power Modules 1-46
Remote Interface PWB Replacement 1-53
Cooling Fan Replacement 1-55
Reject Load or Reject Load/Splitter Interface Assembly Replacement 1-57
Controller Replacement 1-60
Single-Board Computer (SBC) Replacement 1-62
Controller PWB Replacement - Controller 1-65
Exciter Replacement 1-67
Exciter/Control PWB Replacement - Exciter 1-69
Pre-Amplifier PWB Replacement - Exciter 1-72
Module Control/Interface PWB Replacement 1-75
Power Supply Interface PWB Replacement 1-78
UPS Interface Power Supply Replacement 1-79
Power Module Combiner PWB (NAPH06) Replacement 1-81
Power Module Combiner PWB (PR82C) Replacement 1-84

GV40/GV30 TROUBLESHOOTING MANUAL TABLE OF CONTENTS
PAGE 4.VI VERSION 4.0 2018-02-26
Parts Lists 2-1
Family Tree 2-1
How to Locate Information About a Specific Part 2-1
Column Content 2-2
Wiring/connector lists 3-1
Wiring Lists Provided 3-1
Wiring Lists Not Provided 3-1
Connector Mating Information 3-1
Wire Colours 3-1
Printed Wiring Board Patterns 3-1
Reading Electrical Schematics 4-1
Component Values 4-1
Graphic and Logic Symbols 4-1
Reference Designations 4-1
Unique Symbols 4-2
Identifying Schematic Diagrams 4-2
Structure of Schematics 4-3
Locating Schematic Diagram(s) for a Functional Block 4-3
Locating a Part or Assembly on a Schematic 4-4
Mechanical Drawings 5-1
Identifying Mechanical Drawings 5-1
Content of Mechanical Drawings 5-1
Locating a Part or Assembly on a Mechanical Drawing 5-1
List of terms 6-1

GV40/GV30 TROUBLESHOOTING MANUAL
VERSION 4.0 2018-02-26 PAGE 4.VII
RELEASE CONTROL RECORD
ISSUE DATE REASON
4.0 2018-02-26 Release 4 of GV40/GV30 (NARF75C/02). Supports software
version GV SW 4.4.1 or later.

GV40/GV30 TROUBLESHOOTING MANUAL
PAGE 4.VIII VERSION 4.0 2018-02-26

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
VERSION 4.0 2018-02-26 PAGE 4.1.1
SECTION 4.1: RESPONDING TO ALARMS
This section provides instructions you need when performing troubleshooting on the GV40/GV30
transmitter. This section includes the following topics:
Corrective Maintenance
Electrostatic Protection - see page 4.1.3
Identifying an Alarm - see page 4.1.4
Accessing the Inside of the Transmitter - see page 4.1.32
Troubleshooting Tips - see page 4.1.33
Replacement Procedures - see page 4.1.43
If none of the procedures and alarms described in this section address your problem, contact Nautel for
assistance. See “Technical Support” in the Pre-Installation Manual.
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.
On-Air Troubleshooting
On-air troubleshooting can be performed from a remote location, or locally at the transmitter site.
CAUTION! The transmitter contains many solid state devices that may be damaged
if subjected to excessive heat or high voltage transients. Take every effort to ensure
that circuits are not overdriven or disconnected from their loads while turned on.

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PAGE 4.1.2 VERSION 4.0 2018-02-26
Remote Troubleshooting
Remote on-air troubleshooting consists of monitoring the transmitter's radiated signal using an on-air
monitor or via a LAN connection, 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). It is recommended that the significance of
remote indications, and the appropriate responses, be incorporated into a station's standard operating
procedures. Refer to “Identifying an Alarm” on page 4.1.4 to determine the remedial action required for
a given fault.
Local Troubleshooting
Local on-air troubleshooting consists of monitoring the transmitter's integral meters and fault alarm
indicators. Analysis of this data will normally identify the type of fault, and in most cases will determine
what corrective action must be taken. Refer to “Identifying an Alarm” on page 4.1.4 to determine the
remedial action required for a given fault.
The power amplifier stage contains an integral modular reserve (IMR) feature. This feature permits the
transmitter to operate at a reduced RF output level when a malfunction occurs in one of its power
modules. Station operating procedures will dictate whether a reduced RF output level is acceptable.
When a reduced RF output level can be tolerated, replacement of the defective RF power module may
be deferred to a convenient time.
A defective RF power module may be removed from the transmitter for servicing, while the transmitter
is operating, provided that the conditions in the removal instructions detailed in “Removing an RF Power
Module” on page 4.1.44 are met.
Off-Air Troubleshooting
Off-air troubleshooting must be performed when the replacement of a defective RF power amplifier
module, or routine on-air calibration adjustments, will not restore operation.
It is recommended that the transmitter’s output be connected to a precision 50 resistive dummy load
(rated for at least the maximum transmitter power rating) before starting off-air troubleshooting
procedures. If an appropriate dummy load is not available, troubleshooting for a majority of faults can
be performed with RF power stage turned off. The transmitter may remain connected to its antenna
system for these procedures.
NOTE: Reduce the RF output level to a minimal value when troubleshooting faults in the power
amplifier stage while the transmitter’s RF output is connected to the antenna system.

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VERSION 4.0 2018-02-26 PAGE 4.1.3
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.
Electrical Discharging of Personnel
Personnel should be electrically discharged by a suitable grounding system (e.g., anti-static mats,
grounding straps) when removing an assembly from the transmitter, and while handling the assembly
for maintenance procedures.
Handling/Storage
An assembly should be placed in an anti-static bag when it is not installed in a host transmitter, or
when it is not undergoing maintenance. Electronic components should be stored in anti-static
materials.
Tools/Test Equipment
Testing and maintenance equipment – including soldering and unsoldering tools – should be suitable
(i.e., grounded tip) for contact with static sensitive semiconductor devices.
Stress Current Protection
Every precaution should be taken to ensure the static sensitive semiconductor devices are protected
from unnecessary stress current. This is achieved by ensuring that current is not flowing when an
electrical connection is broken, and that voltages are not present on external control/monitoring circuits
when they are connected.
CAUTION! Electrostatic energy is produced when two insulating materials are
rubbed together. A person wearing rubber-soled shoes, walking across a nylon
carpet or a waxed floor, can generate an extremely large electrostatic charge. This
effect is magnified during periods of low humidity. Semiconductor devices such as
integrated circuits, field-effect transistors, thyristors and Schottky diodes may be
damaged by this high voltage unless adequate precautions are taken.

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
PAGE 4.1.4 VERSION 4.0 2018-02-26
Identifying an Alarm
You can identify an alarm locally by viewing the local or remote AUI’s Transmitter Status page (see
“AUI Transmitter Status Page Checks”). As a backup option, you can also view the front panel of the
controller module (A4) (see “Controller Module Front Panel Alarm Checks” on page 4.1.7).
AUI Transmitter Status Page Checks
If an alarm exists and is being recognized by the transmitter (i.e., the Status button at the bottom of
the AUI display will be red), it is displayed on the transmitter status page (see Figure 4.1.1 on page
4.1.5). The Device name indicates the sub-system origin of the alarm. The sub-systems that can be
displayed are:
Controller: All alarms in this sub-system apply to the controller.
Exciter A or B: All alarms in this sub-system apply to an exciter (A or B).
Rack #: All alarms in this sub-system apply to a rack (cabinet) (4 for GV40/GV30).
RF Module #: All alarms in this sub-system apply to a specific RF power module (1 through 16)

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
VERSION 4.0 2018-02-26 PAGE 4.1.5
Figure 4.1.1: Transmitter Status Page
1. Click the Status button to go to the Transmitter Status page (see Figure 4.1.1). View the list of
active faults. Alarms are listed by their origin (Device column), then by name (Alarm column), and
then by severity (Level column) [single orange ! indicates low severity (RF output not affected);
single red ! indicates medium severity (RF output is reduced); two red ! indicates high severity (RF
output is inhibited)].
2. Attempt to clear any latching alarms by pressing the Reset button on the bottom banner of the
page. If the alarm persists, it will not be cleared from the display.
3. Locate the alarm name in Table 4.1.1 on page 4.1.10 to determine the cause of the alarm and
perform any recommended procedures in the Description and Troubleshooting Action column.
This may also lead to replacing a suspect PWB, power supply or fan, as detailed in “Replacement
Procedures” on page 4.1.43.

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
PAGE 4.1.6 VERSION 4.0 2018-02-26
NOTE: Table 4.1.1 on page 4.1.10 contains a column for most Alarms that can occur, sorted
alphanumerically for each sub-system, including both the names displayed on the AUI and, if different,
the controller UI (in parentheses). The Description and Troubleshooting Action column provides a
brief description of the alarm, troubleshooting tips and a cross-reference to more detailed
troubleshooting, as applicable.
4. If troubleshooting and subsequent replacement of a suspect PWB or module causes the alarm to
disappear from the Transmitter Status page, the alarm has been successfully cleared. If the fault
condition does not clear, 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. Record all alarms. The most convenient way to
do this is by using the remote AUI’s User Settings -> Critical Parameters page to capture and copy all
alarms (see “Capturing Critical Parameters” on page 3.2.147 of the Operations & Maintenance Manual).
Another method is to use a web browser over a LAN connection to save screen shots of critical status,
meter and alarm pages. From the Meter List View page, press the information (i) button for each sub-
device (Controller, Exciter, Rack and Modules) to view (and save) detailed information (see “Viewing
Real-Time Meters - using the AUI” on page 3.2.51 of the Operations & Maintenance Manual).

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
VERSION 4.0 2018-02-26 PAGE 4.1.7
Controller Module Front Panel Alarm Checks
There two ways to check for alarms on the front panel:
Alarm/Status LEDs
View Alarms Screen - see page 4.1.8
Alarm/Status LEDs
There are four LEDs on the left-hand side of the LCD display that provide information about the
operational status of various sections of the transmitter - Exciter, Power Amplifier, Output Network
and Power Supply (see Figure 4.1.2). The LEDs can glow green, amber or red. Typically, green indicates
normal operation, amber indicates a warning, and red indicates a fault or error.
Figure 4.1.2: Controller Module Alarm/Status LEDs
When an LED is:
Green - transmitter is on, with no known faults.
Amber - a fault is present that may cause a reduction in RF power, but the transmitter is still
producing RF power.
Red - a fault is present and the transmitter is not producing RF power.
When a fault is present, the transmitter may still produce an RF output. In this case, or if the transmitter
has shut down, you should schedule and commence more in-depth fault diagnosis. See “View Alarms
Screen” on page 4.1.8.
Exciter
Power Amplifier
Output Network
Power Supply

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
PAGE 4.1.8 VERSION 4.0 2018-02-26
View Alarms Screen
If an alarm exists and is currently being recognized by the transmitter system, it is displayed in the View
Alarms screen (Main Menu -> View Status -> View Alarms) of the controller UI display (see
Figure 4.1.3).
Figure 4.1.3: View Alarms Screen
1. Scroll through the View Alarms screen to view the active faults.
2. Attempt to clear any latching alarms by pressing the checkmark button in the Main Menu ->
Reset Alarms screen. If the alarm persists, it will not clear from the display.
3. Locate the alarm name in Table 4.1.1 on page 4.1.10 to determine the cause of the alarm and
perform any recommended procedures in the Description and Troubleshooting Action column.
This may also lead to replacing a suspect PWB, power supply or fan, as detailed in “Replacement
Procedures” on page 4.1.43.
NOTE: Before undertaking any troubleshooting, record all meter readings and note if any other alarms
are displayed on the View Alarms page. Record all alarms.
NOTE: Table 4.1.1 on page 4.1.10 contains a column for most Alarms that can occur, sorted
alphanumerically for each sub-system, including both the names displayed on the AUI and, if different,
the controller UI (in parentheses). The Description and Troubleshooting Action column provides a
brief description of the alarm, troubleshooting tips and a cross-reference to more detailed
troubleshooting, as applicable. The Front Panel LED (color) column gives a brief description of the
severity of the alarm recorded by the Controller/Exciter. Green indicated operational with no faults,
Amber indicates a non-critical fault and Red indicates an inhibiting fault.
4. If troubleshooting and subsequent replacement of a suspect PWB or module causes the alarm to
disappear from the View Alarms screen, the alarm has been successfully cleared. If the fault
condition does not clear, contact Nautel.

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
VERSION 4.0 2018-02-26 PAGE 4.1.9
Exciter Front Panel Alarm Checks
There are two LEDs on the left-hand side of the Exciter that provide information about its operational
status - Power and Status (see Figure 4.1.4). The Power LED will illuminate green when a valid LVPS
input voltage is applied to the A2J1 connector and +5V is present to power the LED. The tri-color Status
LED can be green, amber or red and be solid or blinking.
When the Status LED is:
Green (solid) - exciter is operational, with no known faults
Amber (solid) - controlled inhibit
Red (solid) - inhibiting fault
Green/Amber (blinking) - exciter is operational with non-critical faults
Green/Red (blinking) - exciter is operational with critical faults
Amber/Red (blinking) - inhibiting fault (latching)
Figure 4.1.4: Exciter Front Panel

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
PAGE 4.1.10 VERSION 4.0 2018-02-26
Table 4.1.1: Troubleshooting Alarms
Device and
Alarm Name
(AUI, UI)
Controller Front
Panel LED (color) Description and Troubleshooting Action
Controller: AC
Summary (AC Summ)
- Not displayed in AUI or UI status. Configurable as a remote output. This
alarms occurs if there are any ac input related alarms present. Check for
other specific ac fault alarms.
Controller: All PAs
Inactive
Power Amplifier (red) This alarm indicates that all of the transmitter’s power amplifiers are
inactive due to external conditions such as ac loss, removal of power supply
modules or RF power modules, or faults in the power supply modules or RF
power modules. If there are power supply module or RF power module
related alarms present, follow the associated troubleshooting procedure.
Controller: Audio Loss
Summary
Exciter (red) Not displayed in AUI or UI status. Configurable as a remote output. This
alarms occurs if there are any audio loss alarms present. Check for specific
audio loss alarms and troubleshoot accordingly. Ensure the preset audio
settings agree with the audio being applied to the exciter.
Controller: Auto
Changeover Occurred
(Auto Changeover)
Exciter (amber) This alarm occurs when the controller has initiated an exciter changeover to
the standby exciter, due to a possible fault with the main exciter.
Controller:
Changeover in
Progress (In
Changeover)
Exciter (red) This alarm occurs only while an exciter changeover is in progress. It will
clear once the changeover is complete.
Controller: Combiner
Match
Output Network (red) This alarm occurs if there is an excessive amount of power in the transmitter
combining stage that cannot be accounted for. This may be the result of a
fault in the combiner.
Controller: Config File
Not Found (Cfg File
Not Found)
Exciter (red) This alarm occurs when the controller does not find a valid configuration file
to load at power-up. This alarm is unlikely, but may occur during
replacement of a controller module. It clears when the correct settings are
entered.
Controller: CPLD
Version Mismatch
(CPLD Ver Mismatch)
Exciter (red) This alarm occurs when there is an incompatible software release in the
controller module’s CPLD. Update the software to clear the fault.
Controller: Current
Imbalance
Output Network (red) This alarm occurs if the Combiner Match alarm occurs due to a PA current
imbalance in the RF power modules

GV40/GV30 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
VERSION 4.0 2018-02-26 PAGE 4.1.11
Controller: Cutback
Active
Output Network
(amber)
This alarm occurs whenever the transmitter experiences a cutback. A
cutback (reduction in power) occurs when repeated shutback alarms occur
within a prescribed time period. Shutbacks occur when the transmitter's
peak reflected power exceeds 2:1 due to a transient SWR condition (arc or
lightning) within the output transmission line or antenna system. The
transmitter shuts back and recovers to a series of cutback levels (depending
on the severity of the alarm), with each level being a 15% reduction in
power from the power attained before the last shutback. Inspect the output
transmission line for punctures or damage. After repairing damage, or if no
damage is found, attempt to reset the latched condition.
Controller: Digital
Player Audio Low
Exciter (red) This alarms occurs if the audio player is in use on the SBC, but no digital
audio is detected by the controller.
Controller:
Discharging PA Volts
(Discharging PA V)
PS (red) This alarm occurs when the transmitter has initiated a shutback sequence,
and residual PA voltage energy stored in the capacitors in the power
supplies and PAs is being discharged. During a shutback sequence, the RF
drive to the PAs is turned off immediately after the event, and this occurs
faster than the power supply modules can be inhibited. Therefore, PA
voltage is still being applied to the capacitors with no drive to discharge the
energy. To discharge the stored energy from the capacitors, the PA bias is
increased to a discharge level after the power supplies have been inhibited.
This causes the stored energy to be dissipated through dc current in the FET.
This alarm should only occur with a Residual PA Volts Present alarm. See
Residual PA Volts Present alarm for more information.
Controller: Door Open Exciter (amber) This alarm occurs if the transmitter’s front door is open, which inhibits the
monitor cooling fans.
Controller: Entered
Firmware Upgrade
(Entr Firmware Upgr)
Exciter (red) This alarm occurs when the transmitter is in “firmware upgrade” mode. It
should only be displayed during a transmitter software upgrade.
Controller: Exciter A
or B Offline
Exciter (red) This alarm occurs if the serial communication fails between the controller
and the exciter, or a problem has occurred with the exciter. Check all
connections to the exciter and make sure that its controller front panel
power LED is on.
Controller: Exciter
Audio Reset
Exciter (red) This alarms occurs if the audio processing within the exciter required a
reset. if this alarm is re-occurring, replace the controller (see “Controller
Replacement” on page 4.1.60).
Controller: Exciter
Summary (Exciter
Summ)
Exciter (amber) This alarms occurs if there are any exciter related alarms present. Check for
specific exciter related alarms.
Device and
Alarm Name
(AUI, UI)
Controller Front
Panel LED (color) Description and Troubleshooting Action

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Controller: External
Interlock Open
(External Interlock)
Exciter (red) The external interlock input wired to the controller (A4) or optional remote
interface PWB (A16), if used, is open. Check the interlock connection
between REMOTE I/O-A pins 19 and 20 on the controller (verify a ground
potential at pin 19) or optional remote interface PWB J2 pins 19 and 20 or
TB1-1 and 2. If the interlock is intact, check all external interlock switches.
Otherwise, suspect a problem with the interlock circuitry on the controller
or optional remote interface PWB.
Controller: External
Summary
- Not displayed in AUI or UI status. Configurable as a remote output.This
alarms occurs if there are any external related alarms present. Check for
specific external related alarms and troubleshoot accordingly.
Controller: Fan Fail Output Network
(amber)
This is an indicational alarm only that is displayed when the controller’s
cooling fan has been enabled and the speed of the fan is below 2000 RPM.
Controller: Final
Reject Fan 1 - 3 Fail
(Final Rej Fan1-3 Fail)
Output Network
(amber)
This alarm occurs if the final reject load (A52) cooling fans are enabled and
the speed of a cooling fan [B10 (1), B11 (2) or B12 (3)] is below 2000 RPM.
Final reject load cooling fans are enabled only when the reject load power is
greater than 300 W, possibly due to an RF power module removal or failure.
Inspect the fan and, if necessary, replace it (see “Cooling Fan
Replacement” on page 4.1.55).
Controller: Forward
Power Limiting (Fwd
Power Limiting)
Output Network
(amber)
When the High Forward Power alarm is active, this alarm occurs if the high
forward power limiting threshold is exceeded [1.063 times the maximum
power setting for all modes; e.g., 46,772 W (GV40) or 35,080 W (GV30) for
FM mode]. The transmitter will fold back the forward power each time the
threshold is exceeded. This alarm occurs only if the controller ALC cannot
respond fast enough to transmitter load changes. Suspect the module
control/interface PWB (A3).
Controller: Forward
Power Shutdown
(Fwd Power
Shutdown)
Output Network (red) This alarm occurs if the transmitter tries to reduce the forward power below
minimum due to repeated Forward Power Limiting alarms. The transmitter
latches off. See Controller: Forward Power Limiting for troubleshooting tips.
Controller: High
Forward Power (High
Fwd Power)
Output Network
(amber)
This alarm occurs if the transmitter’s average forward power exceeds the
high forward power threshold [1.036 times the maximum power setting for
all modes; e.g., 45,584 W (GV40) or 34,188 W (GV30) for FM mode]. This
alarm occurs only if the controller ALC cannot respond fast enough to
transmitter load changes. Suspect the module control/interface PWB (A3).
Controller: High
Reflected Summary
Output Network
(amber)
Not displayed in AUI or UI status. Configurable as a remote output.This
alarms occurs if there are alarms present that are related to high reflected
power on the transmitter’s RF output. Check for specific reflected power
related alarms and troubleshoot accordingly.
Device and
Alarm Name
(AUI, UI)
Controller Front
Panel LED (color) Description and Troubleshooting Action