Comtech EF Data SDM-300A - Manual (Page 60)

SDM-300A Satellite Modem Revision 6
Installation/Upgrades MN/SDM300A.IOM
3–4
3.3 Software and Hardware Installation/Upgrades
3.3.1 Overhead Interface PCB Installation
The overhead interface PCB may be installed at the factory or in the field. The overhead
interface PCB is required to access certain options and functionality of the modem. Observe the
following:
• If the overhead interface PCB is installed at the factory, then the 50-pin interface relay
card will be pre-installed.
• If the overhead interface PCB is installed in the field, then one of four connector/card
combinations will have been shipped with the overhead interface PCB.
CAUTION
This equipment contains parts and assemblies sensitive to damage by ESD.
Use ESD precautionary procedures when touching, removing, or inserting
PCBs.
The following tool is required to install the overhead interface PCB:
Description Application
Phillips  Screwdriver To remove and replace cross-point screws.
Use the following information to install the overhead interface PCB as a daughter card on the
main PCB. Refer to Figure 3-2 for the installation location of the overhead interface daughter
card.
CAUTION
Turn the power off before installation. High current VDC is present. Failure
to do so could result in damage to the modem components.
1. Turn off the modem and unplug the power supply.
2. Remove the rear panel retaining screws. Using the finger pulls, slide the main modem
assembly out from the rear of the modem chassis.
3. Install the overhead interface PCB, face down, onto the main PCB by mating the male
header connectors with the female header connectors in the position shown in
Figure 3-2.
4. Align the overhead interface PCB standoffs with the main PCB mounting holes. Install
the four mounting screws and washers.