4
February 1996
3610-A2-GZ43-20
Model 3611 Firmware
Installation
To access the DSU to install the firmware in a
Model 3611 DSU, perform the following steps:
.
Procedure
1. Use a Phillips screwdriver to loosen the screw
holding the circuit pack lock, and rotate the lock
to the open position. With a MUX card installed,
open both circuit pack locks. It is not necessary to
power down the carrier.
Circuit
Card
Guides
Circuit
Pack
Lock
Latch
Open
(Unlocked)
Closed
(Locked)
495-14813
2. Pull out and down on the latch at the bottom of the
DSU’s faceplate until the circuit card starts to
come out of its slot in the carrier. Pull the DSU
circuit card free of the carrier and lay on a clean
flat work surface. When a MUX card is installed,
there are two latches to open. (See next section.)
Accessing a Model 3611 DSU with MUX
.
Procedure
1. Remove the 3611 DSU with a MUX. The MUX
card for TDM or MCMP is attached to the DSU.
Together, the two cards use two carrier slots.
495-14827
DSU
Card
MUX
Card
2. Remove the two standoff posts and the four
double-ended, Phillips-head screws to detach the
MUX card from the DSU card.
MUX Card
DSU Card
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Phillips-Head
Screws
Standoff
Posts
Flat
Washers
495-14828
