
UPGRADE PROCESS
Remove, Upgrade, Replace, and Test TN711 Circuit Pack
SYSTEM 75
The TN711 Processor circuit pack must be vintage 11 or 12 and must be
known to be operational before it can’ be upgraded on site.
Power Down System
1.
At the maintenance board (Figure 6), set the
TRANSFER CONTROL switch to ON. This locks the
transfer mode until the circuit packs are installed.
EMERGENCY
system in the
2. At the power distribution “unit (Figure 7), set the main ac circuit
breaker to OFF.
Remove, Upgrade, and Replace TN711 Circuit Pack
Warning:
A wrist strap must always be worn and the clip must be
grounded to the carrier frame being worked on before
inserting or removing any circuit pack.
1.
2.
3.
4.
5.
See Figures 1, 2, and 3. Remove the
(see Note).
Note:
The IC38 and IC39 must
board can be upgraded on
TN711 Processor circuit pack
be socketed before this
site.
See Figure 8. Position the TN711 circuit pack so that the component
side is up, with connector to the left.
Clip and discard tie wraps (if provided) holding IC38 and IC39 in the
sockets.
See Caution. Remove IC38
tool T-114-1, or equivalent.
kit.)
and IC39 from the TN711 using IC puller
(Tool is included in the D-181429 parts
Caution:
Be sure tool is not under socket body. The
socket will be ruined if pulled from the board.
See Caution. Remove the new lC38 and IC39 from antistatic plastic
tube.
Caution:
The pins of the ICS are lubricated to prevent
contact corrosion.
The lubricant must not be
wiped off.
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