Service manual

8. Remove the center shield from the chassis by
inserting a thin slotted screwdriver between each
of five center-shield release clips and the corre-
sponding chassis-retaining tabs.
Once freed from the chassis at the five release
points, the center shield can be removed and the
RF board can be removed from the chassis.
B. Servicing Major Subassemblies
Refer to the exploded view diagram at the back of
this manual before attempting further disassembly or
repair.
1. Baseplate
• All repairs to the baseplate assembly can, and
should, be made with the radio chassis inside
the radio.
• After the slotted-spanner nuts are loosened,
the baseplate is held in place by the power
contact screw.
• The retainers holding the slotted-spanner nuts
in place are not reusable. Replacement of the
retainers requires special insertion proce-
dures; refer to the instruction sheet provided
with the slotted-spanner nut kit.
• The "O-ring" portion of the elastomer seal
must be fully seated on the threaded bushing
before the baseplate is reassembled (the
bushing is part of the housing assembly).
2. Housing Assembly
• The housing assembly includes many parts
that are not replaceable or repairable.
• The insulator on the universal connector can,
and should, be replaced if the old insulator
has been torn. When replacing the insulator
take care to keep it out of the main-seal
O-ring's seating area.
• The PTT lever can be replaced by prying out
the old part with a soft plastic tool. The plastic
housing around the lever may be damaged if
a harder tool is used.
3. Control Top Panel
The control top panel is fastened to the chassis by
the on/off/volume control, mode/zone selector
switch, programmable switch, and antenna switch;
it should be removed from the chassis only if
absolutely necessary.
4. Front Shield/Display Board Assembly
The ASTRO Digital SABER radio's display board
can be replaced, but the comments and cautions
in this manual must be strictly followed. To remove
the display board from the front shield assembly:
a. ensure that all static safeguards are in effect;
b. turn the front shield/display board assembly
face down;
c. with slight upward pressure on the LCD bezel,
bend back each of the two plastic tabs that
hold the display board in place, and the bot-
tom of the LCD will come loose;
d. push the LCD from its secured position
enough to grasp its edges, then pull firmly up
and out on the front shield/display board
assembly.
5. Chassis
If you must lift or remove the control top/PTT flexi-
ble circuit for any reason, do not re-adhere it to the
chassis; the flexible circuit must be replaced.
6. Dual-Function Switch and Actuator Assembly
• Before removing the switch, remove the knob
by gently separating the two arms of the
switch bracket (located between the switch
and the main O-ring seal) and pulling upward
on the knob.
• Before re-inserting the knob, ensure that the
slot in the switch is properly aligned with the
blade on the knob's shaft.
21
CAUTION
Use extreme caution to ensure that the release
clips are only deflected enough to disengage
the clip from the chassis. Too much pressure on
the clips could permanently damage the retain-
ing feature.
CHASSIS WITH
RF BOARD ASSEMBLY
MAEPF-23378-
O
CENTER SHIELD
RELEASE POINTS
(5)
CENTER SHIELD
(UNDERNEATH)
MAEPF-23378-O
CAUTION
The RF and ground contacts at the top of the RF
board are exposed when the board is removed
from the chassis. Special care must be taken to
avoid accidental damage to these contacts.
CAUTION
Be very careful not to damage the keyswitch
overlay which is adhesively attached to the
LCD bezel.