User's Manual

Lucent Technologies — Proprietary
See notice on first page
22-40
401-660-100 Issue 11 August 2000
Linear Amplifier Circuit (LAC) Maintenance
LAMs near the bottom of the LAU and use a flashlight to check the position
of the switch. (There are actually two switches, but only the upper one is
used.) Insert a scribe, or other pointed tool, into the circular indent in the
upper slide switch, making sure that the switch is positioned toward the
front of the LAC.
2. If the position is wrong, change it and check to verify that the alarm has
cleared. (In some cases it may take a few minutes for the alarm to clear.)
NOTE:
In recently produced LACs the FAC/FLD switch was moved to the front of
the Linearizer (See Figure 22-10) to allow easier access. LACs with this
feature have a 6-position dip switch in place of the 5-position switch. The
top switch, labeled "1", is used for the FAC/FLD setting and the bottom 5
switches, labeled 2-6, are used for the address setting. The top switch
should be in the "0" position for field operation. LACs with this feature are
clearly marked.
Checking the Version of the Microprocessor Firmware
A/B Series LACs with AYE1 circuit packs prior to Version 7 do not store processor
alarm information, making it impossible to tell if the LAC has issued a Processor
alarm. If the SERIES number on the AYE1 circuit pack is from 1 to 6 (the label is
located on the top front corner of the pack), the microprocessor should be
replaced with one having the latest firmware. (If the AYE1 pack does not have a
SERIES number label, it is an old version - replace the processor.) Refer to AT&T
Engineering Change Procedure ECP-C20144CB for details on how to replace the
microprocessor.
NOTE:
The LAC Alarm Query System (LAQS) may display an error message when
attempting to communicate with an LAC which does not store processor
information.
When upgrading the microprocessor:
1. Be sure to turn off all radios and power down the LAC beforehand.
2. After replacing the microprocessor, be sure to follow the instructions for
labeling the AYE1 circuit pack to show that it has been upgraded.
3. Before re-applying power, make sure that all radios are off. Re-apply power
first to the Linearizer and then to the LAU.
4. Turn on 2 radios and allow the LAC to adjust for 2 minutes. Bring up all
radios. If the alarm repeats, proceed with the next section to query the
microprocessor alarm registers to determine if the LAC has issued a
Processor alarm.