4-25

Control Panel Servicing

Replacing Control Panel Modules
The locations of control panel circuit modules and mezzanines are
illustrated in Figure 4-11.
To remove a circuit module assembly from the control panel, proceed as
follows:
WARNING
If the redundant power supply is installed, Both power supplies must be
turned off and both power cords must be unplugged.
1. Turn off the AC power at the switch located on the left end of the power
supply enclosure inside the control panel. See Figure 4-11.
2. Unplug the AC line cord from the AC source. The AC line cord is
located at the rear of the control panel.
3. On the top of the control panel, remove any control knobs, lever arm
T-handles, etc. that would interfere with removing the assembly.
NOTE:
If the lower right switch module is to be removed, the plug from the
joystick/positioner must be unplugged from the side of the module (under the top
of the control panel at the rear of the positioner) before lowering the module out of
the control panel. It is not necessary to remove the positioner to remove the switch
module.
4. Open the control panel and locate the module to be replaced.
5. Disconnect any cables or wiring that are attached to the module being
removed.
CAUTION
Use care when removing cables or wiring to prevent the bending of connector pins
or damage to cable assemblies. Damage of this type can result in improper
operation or damage to other circuit modules.