AT&T 3.0 manual Beware of hazardous voltages

Upgrading the Control Unit

aRemove the rightmost module from the control unit. See “Removing a Module” in Chapter 2 for instructions.

bUsing a flat-blade screwdriver, unscrew the upper-right corner of the carrier only far enough to free the clip.

cPull the top-right corner of the carrier toward you while grasping the housing clip and pushing it away from you (to free it from the carrier).

dWhen the clip is free enough to clear the screw molding on the back of the carrier, slide the clip out and discard it.

eCompare the Control Unit Diagram with the existing control unit. If you are installing an additional expansion carrier in this upgrade, do not replace the clips on the right side until the last expansion carrier is installed. If no more carriers are to be installed, replace the clip now, making sure the clip is as far to the right as possible.

fSecure the screw, and then repeat Steps b, c, and d for the lower right corner of the carrier.

2Remove the power supply module to access the housing clips on the leftmost side of the carrier. See Figure 9-3.

aPress up on the tab at the bottom rear of the power supply.

bWhile the tab is unlocked, pull the power supply towards you, and then lift it straight up.

WARNING:

Beware of hazardous voltages.

Whenever the carrier connections are exposed, use extreme caution; do not touch them directly or with any type of tool.

Follow all procedures carefully.

9-8Upgrading the System