User's Manual
Manual 7-9386-1 Page 22TX RX Systems Inc. 09/30/04
61-68-50 UserMan page 22 of 25
Modules can be swapped between the uplink and
downlink branches for troubleshooting purposes. If
a problem exists in one branch and the problem
moves to the other branch when modules are
swapped around this indicates a defective module.
Note:
After an amplifier module is
replaced use the Calibrate Currents
software function to properly set the
amplifiers alarm trip point, see page
10. Due to slight differences in compo-
nent tolerances the trip point must be reset for any
new amplifier assemblies introduced into the sys-
tem.
Display/User Interface Assembly Replacement
The SB II Display/User Interface assembly is field
replaceable. Follow the steps listed below in
sequential order. No tools are required.
Note:
Power to the SB II cabinet must
be turned OFF during the display/user
interface replacement process.
1) Loosen the two thumb-nuts which hold the dis-
play/user interface assembly to the card cage.
2) Gently tilt only the top of the assembly up from
the card cage. Keep the bottom of the assembly
in place. The bottom mounting plate (part of the
card cage) has an overhang on it to support the
display/user interface board. If the assembly is
lifted straight out the overhang could possibly
damage the interface circuit board.
3) With the display/user interface board standing
up straight gently move it upwards while lifting it
out about an inch or two. This should allow the
overhang to clear the interface circuit board
without damage.
4) Remove the ribbon cable that connects the dis-
play/user interface assembly to the card cage,
see
Figure 13
.
5) To replace the display/user interface assembly
repeat steps 1 through 4 in reverse order.
NOTE
NOTE
Figure 13
: Disconnecting the display/user interface assembly from the card cage.
Disconnect
ribbon cable
here