Specifications

1-11 PREVENTIVE
MAINTENANCE
The MS462XX VNMS requires periodic cleaning of the cooling fan
screen to prevent an obstruction that could facilitate overheating.
Additional maintenance that may be required includes replacing a
blown fuse, replacing the CPU backup battery, and replacing the LCD
backlight. This additional maintenance is outlined below:
Fuses The MS462XX contains three fuses, two internal
and one external. The external, rear-panel-mounted
fuse is rated at 5A, 250V, F (quick acting). It is de
-
signed to blow first in the event of an over-current
condition. Of the two internal fuses, one is rated at
6.3A, 250V, F (quick acting), and the other at 15A,
32Vdc (automotive type). Neither of the internal
fuses are replaceable at the field level. They are
mounted within the field-replaceable power supply
module. Internal fuse information is provided for
reference only.
CPU Backup
Battery
The MS462XX CPU module contains a lithium bat-
tery that powers the instrument’s hard drive. When
this battery becomes discharged, you may observe
the following:
q Inability to view the contents of the hard
drive
q Inability to save or recall hard drive files
(Error 7172 Hard Disk Read Error)
q GPIB address changes after cycling the
instrument power
q
Self test fails and displays a battery failure
message
The life of the CPU battery is dependant on instru
-
ment use. For example, the maximum life expec
-
tancy of the CPU battery is 2.8 years when the
instrument is stored in an unused state (always
powered off), and 5 years when the instrument is in
continual use (always powered on). Anritsu service
centers recommend a proactive approach to main
-
taining the CPU battery by replacing it every three
years. Refer this maintenance to a qualified Anritsu
service center.
LCD Backlight The MS462XX LCD display contains a backlight
flourescent lamp that has a rated life span of
50,000-hours. The LCD backlight may need to be re
-
placed after this life span has elapsed. Refer this
maintenance to a qualified Anritsu service center.
GENERAL PREVENTIVE
INFORMATION MAINTENANCE
MS462XX OM 1-9