Nautel NX15, Troubleshooting Manual

Page: 68 / 274

NX25/NX15 Troubleshooting Manual Responding to alarms
Page 1-60 Issue 5.0 2016-05-06
Control/interface PWB replacement
1. Record the following information (as a minimum) from the front panel AUI:
– Presets
page: record settings for all desired presets
–
Scheduler
page: record
Rules
and
Daily Events
information
–
Factory Settings
page: record information in the
RF Symmetry
and
Transmitter Type
menus
–
System Settings
page: record all information in the
Exciter Clock Calibration
and
Power Lockout
menus
–
User Settings
page: record all information in the
Network Setup
menu
–
Remote I/O
page: record all information for the user-defined remote
Inputs
and
Outputs
, including
Channel
and
Control
settings
–
Changeover
page: record all information
2. Use a digital multimeter to measure the VSWR threshold voltage on the control/interface
PWB at R73-LHS. Record this voltage.
3. Set the transmitter to its
RF Off
state. Turn off (disable or lock out) the ac power at the
source. Open the front door to gain access to the exciter panel (see Figure 1.6 on page 1-54 ).
4. Disconnect all cables attached to the control/interface PWB (A4), taking note of the
connector labels on the cables and the PWB.
5. Remove and retain the two screws securing the connector bracket in the upper, left portion
of the control/interface PWB.
6. Remove either the remote interface PWB (A11A4) or both digital AM exciter PWBs (A11A2
and A11A3), whichever is easier. It may be helpful to gently pry the connectors loose with a
screwdriver.
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.
10. Install the new control/interface PWB by reversing Step 4 through Step 7 . For connector
mating assistance, refer to the connector mating tables in Section 4, “Wiring/connector lists”
on page 4-1 .