Orban Optimod-FM 8300 Operating Manual page 193

OPTIMOD-FM DIGITAL
C) Unplug the RS-232 interface assembly from the base board.
4. Removing the CPU Module:
A) Remove the four screws holding the CPU module to the standoffs that sup-
port it on the base board.
B) Applying gentle upward pressure, unplug the CPU module from the base
board.
5. Removing the Base Board:
A) If you have not done so yet, remove the top cover (step 1, above).
B) If you have not done so yet, remove the CPU module (step 4, above).
C) Using a 3/16-inch hex nut driver, remove the two hex nuts holding the DB-25
connector to the rear panel of the chassis.
D) If you have not done so yet, remove the RS-232 connector board (step 3,
above).
E) If you have not done so yet, remove the five cables that connect the display
assembly to the base board.
F) If you have not already done so, remove the RS-232 interface assembly from
the base board (step 3 on page 4-2).
G) Disconnect the ribbon cable connecting the base board to the I/O board.
H) Disconnect the ribbon cable connecting the base board to the DSP board.
I) Disconnect the ribbon cable connecting the power supply to the base board.
J) Using a #1 Philips screwdriver, remove the four corner screws holding the base
board to the chassis standoffs.
K) Using a 3/16-inch hex nut driver, remove the four hex standoffs on which the
CPU module was mounted
L) The base board is now free and can be removed from the chassis.
6. Removing the I/O (Input/Output) Board:
A) If you have not done so yet, remove the top cover (step 1, above).
B) Unlock all six XLR connectors, using a jeweler's screwdriver: engage the lock-
ing mechanism (in the center of the triangle formed by the three contact pins)
and turn counterclockwise until the XLR connector is no longer attached.
C) Using a deep hex nut driver (preferred), a small crescent wrench, or a pair of
slip-joint pliers (in an emergency), remove the four nuts and lockwashers fas-
tening the four BNC connectors to the chassis.
Use great care not to scrape the paint, particularly if you are using pliers.
D) Remove the ribbon cable that connects the I/O board to the base board.
4-3
MAINTENANCE