User's Manual

Field Replaceable Units Nexus FT
4-6 044-05251 Rev C
Field Replaceable Units
The following units can be replaced in the field on-site by a qualified technician with experience maintaining
RF equipment:
❑ FON
❑ PSU
❑ WRH
FON
To replace a FON PCBA, follow the steps listed in Table 4-3. For details on cables and connectors, see
Chapter 2.
CAUTION: Do not look into the end of any fiber optic cable. Be sure to cap fiber optic
cables to protect the connecting end from damage
CAUTION: Use of controls or adjustments or performance of procedures other than
those specified herein may result in hazardous radiation exposure"
NOTE
Verify ‘Fiberoptical’ classmark in the FON Status window is checked, otherwise FON will not be operational.
Classmarks are described in the OM-Online User Manual.
Verify that the keyed angle polished connectors are aligned pr
operly before tightening. Improper alignment
can result in high signal loss and/or no connectivity with that node.
Table 4-3 FON Replacement Procedure
Step Action
1 Loosen all four locking screws on front of cabinet
2 Open WRH door and secure
3 Locate power connector on FON and remove connector from PCBA
4 Verify all cables on FON are labeled before disconnecting, then disconnect all cables.
5 Remove screws securing FON PCBA to FOU and remove PCBA
6 Replace FON PCBA in reverse order and apply power
7 Connect PC to OM Online port, login to FON and verify configuration and IP address.
8 Close WRH door and secure
NOTE
After replacing the FON, if measurements taken at the fiber connector are correct but the OM Online
measurement indicates a loss several dB higher, the likely causes are:
1) Dirty fiber.
2) The DIN to FC bulkhead adapter is bad.
3) Loose fiber connection on the FON board.
4) Bad WDM.