Subassembly Removal And Replacement - Orban OPTIMOD-FM 5500 Operation Manual

4-2
MAINTENANCE

Subassembly Removal and Replacement

See page 6-27 for the Circuit Board Locator and Basic Interconnections diagram.
1. Removing the Top Cover:
To access any internal board (including the display assembly), you must remove
the top cover.
A) Disconnect the 5500 and remove it from the rack.
Be sure power is disconnected before removing the cover.
Warning: Hazardous voltage is exposed with the unit open and the
power ON.
B) Set the unit upright on a padded surface with the front panel facing you.
C) Remove all screws holding the top cover in place, and lift the top cover off.
Use a #1 Phillips screwdriver.
2. Removing the Front Panel Assembly:
A) Detach the cables that connect the display board assembly to the control
board. Avoid bending or breaking the pins. Note the lead dress so you can re-
assemble the unit correctly.
B) Detach the front panel from the unit.
a) On each side of the chassis, remove the three screws close to the front
panel.
b) Remove the front panel by sliding it out.
C) Set the front panel, face down, on a soft cloth to prevent scratches.
D) Using a 3/16-inch hex nut driver, remove the four hex nuts holding the two
side brackets and central shield to the front panel. Remove the brackets and
shield and set them aside.
E) Using a #1 Philips screwdriver, remove and reserve the eight screws and spac-
ers that fasten the display board assembly to the front panel.
F) Lift the display board assembly off its supporting standoffs.
G) Separate the two boards in the display board assembly by carefully unplug-
ging the top board from the bottom board. Note that there are four plugs
and jacks.
3. Removing the Composite/SCA daughterboard.
A) Unplug the cable connecting the Composite/SCA daughterboard to the I/O-
DSP board.
ORBAN MODEL 5500