User's Manual

Manual 7-9410-1.2 Page 21

TX RX Systems Inc. 10/21/05

61-83B-50-XXX-XX UserMan page 21 of 25

card cage. Once the card is seated into place

properly tighten the thumb screws.

The SB II low level and mid level amplifier stages

are field replaceable by simply removing the mod-

ule and plugging in a replacement. These modules

are HOT switchable meaning they can be swapped

without powering down the system. RF cables

attached to the modules must be removed (5/16”

wrench) prior to swapping the modules and must

be re-attached after the new module is in place.

when replacing the RF cables do not overtighten

the SMA connectors. They should be tightened just

slightly more than hand tight or to the specification

of 7 in/lbs.

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 system.

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.

NOTE

Figure 14: Disconnecting the display/user interface assembly from the card cage.

Disconnect

ribbon cable

here