Orban 8300J, Operating Manual

Page: 192 / 280

4-2
MAINTENANCE ORBAN MODEL 8300
Subassembly Removal and Replacement
See page 6-29 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 8300 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 eighteen 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 three ribbon cables that connect the display board assembly to the
base board. Gently lift each cable up from where it connects to its jumper, so
that the jumper pins unseat without bending or breaking.
B) Detach the front panel from the unit.
a) Disconnect the three-wire cable at the back of the encoder.
b) Detach the ground lug that connects the panel's ground wire to the chassis.
Use a ¼-inch nut driver or needle-nose pliers.
c) Remove the front panel.
The front panel is held in place by four ball studs at each corner. The
panel should snap away from the chassis if you apply a little force.
C) Using a screwdriver, remove the ten gold-colored screws and washers that
connect the display board to the front of the chassis.
D) Remove the display board assembly by removing the tape from the top front
edge of the chassis, so that the white ribbon cables are no longer attached to
the chassis and the display panel is free.
Do not remove the tape from the white ribbon cables.
3. Removing the RS-232 Connector Board:
A) If you have not done so yet, remove the top cover (step 1, above).
B) Using a 3/16-inch hex nut driver, remove the two hex nuts holding the RS-232
connector to the chassis.