Nautel V10 - IPA Forward High

V10/V7.5/V5/V3.5 Installation and Operation Manual Page 5-11
Section 5 System Level Troubleshooting Issue 3.5
5.5.2.1 IPA Forward High
An IPA Q3 Fwd High (V10/V7.5), IPA Q4
Fwd High (V10/V7.5) or IPA Fwd High
(V5/V3.5) alarm occurs when the IPA
(specifically A3 or A4 in the V10/V7.5)
peak forward power exceeded the high
IPA forward power threshold (IPA Forward
High threshold is user definable, but is
defaulted to 350 W for FM mode; 200 W
for HD and FM+HD modes). This alarm
will only occur if ALC cannot respond fast
enough to varying IPA load changes or if
ALC is disabled. Five such occurrences
within five minutes will result in the
transmitter response described in 5.5.2. To
reset, press the Reset soft key in the
Status screen. Troubleshoot as follows:
(a) Verify ALC is still enabled for the IPA.
(b) Check for additional front panel alarm
lamps and active faults/events:
NOTE
If an RF power module input drive cable is
defective, the associated switching power
supply will be inhibited due to low RF drive
input level. The associated Module Fail
(A-H for V10; A-C, E-G for V7.5; A-D for
V5, A-C for V3.5) and associated switching
power supply module PS Fail (A-H for V10;
A-C, E-G for V7.5; A-D for V5, A-C for
V3.5) alarms will be on.
• Check cables between the IPA splitter
assembly (A21 or A22, as applicable)
and the applicable RF power module’s
interconnect PWB (A23-A30 for V10,
A23-A25 and A27-A29 for V7.5,
A23-A26 for V5, A23-A25 for V3.5).
These cables/connections include V10:
W11 (A)-W18 (H); V7.5: W11 (A)-W13
(C) and W15 (E)-W17 (G); V5: W11 (A)-
W14 (D); and V3.5: W11 (A)-W13 (C).
• For V7.5/V3.5, check cables between
the IPA splitter assembly (A21 or A22,
as applicable) and the RF termination
assemblies (A47 and A48, as
applicable). These cables include W14
and W18, as applicable.
• Ensure all RF power modules are
online and installed properly.
• If an IPA PS Fail A or B alarm also
occurred, the fault is likely with the
associated IPA switching power supply
module. If transmitter operation has
been interrupted (as in single IPA
transmitters), replace the IPA switching
power supply module with an
operational RF switching power supply
module [see steps (c) and (d)] and
verify the alarm disappears. If the alarm
persists, check the IPA module/PA.
• If cables and connections are secure,
modules are installed properly, and
there appears to be no power supply
faults, there is likely a problem with IPA
splitter assembly A21 or A22 (as
applicable), control/display PWB A43’s
fault detection circuitry, or with the IPA
power module/PA. For dual IPA
systems, if the standby IPA is operating,
there are no faults with the IPA splitter
assembly(ies) or with the control/display
PWB fault detection circuitry.
(c) Before removing a switching power
supply module from the transmitter,
ensure its ON/STANDBY switch is set
to STANDBY (toggle down).
(d) Remove the suspect IPA switching
power supply module and an
operational module. Install the
operational module in the position of
the suspect IPA power supply module.
Set the ON/STANDBY switch to ON.
Press the Reset button in the Status
screen to restore operation.
Possible Associated Faults:
- IPA Q3 or Q4 Fwd High (V10/V7.5)
- IPA Fwd High (V5/V3.5)
- Q3 or Q4 Latch Off (V10/V7.5)
- IPA Latch Off (V5/V3.5)
- IPA PS Fail A or B
- IPA Shutdown
- IPA Fail A or B