Nautel NX15, Troubleshooting Manual

Page: 42 / 274

NX25/NX15 Troubleshooting Manual Responding to alarms
Page 1-34 Issue 5.0 2016-05-06
Rack #: +48 V A (or B)
Fail If the o48 V Fail alarm is active, follow the troubleshooting
steps for that alarm. Otherwise, check continuity of the cabling
between the asso48 V power supply and the rack
interface PWB. If the cabling looks OK, and all connections are
tight, replace the asso48 V power supply
(see “Low
Voltage Power Supply Replacement” on page 1-68 ).
Rack #: +5 V Fail This alarm occurs if the +5 V rail has varied outside its acceptable
range of 4 to 6 V. Suspect a faulty dc-dc converter
on the rack
interface PWB. Replace the rack interface PWB (see “Rack
Interface PWB replacement” on page 1-64 ).
Rack #: +5 V A (or B)
Fail This alarm occurs if the associated +5 V power supply’s output
voltage is outside its acceptable range of 4 to 6 V. Suspect a faulty
dc-dc converter on the rack interface PWB. Replace the rack
interface PWB (see
“Rack Interface PWB replacement” on
page 1-64 ).
Alarm (with Prefix) Description and Troubleshooting Action