Ericsson LBI-38701, Maintenance Manual, Page: 7 / 23

TO REMOVE THE DUPLEXER
INTERFACE BOARD A4
l. Remove the top cover of the radio. Refer to the procedure
above.
2. Disconnect the cables going back to the RF Board.
3. Disconnect the cables from the duplexer.
4. Remove the four M3.5-0.6 TORX screws (#15 drive)
securing the board to the frame. Carefully work the board
out of the radio, unplugging it from the feed through
assembly Z903.
TO REMOVE THE SYSTEM BOARD A5
1. Remove the bottom cover of the radio. Refer to the
procedure above.
2. Disconnect the ribbon cable from J902.
3. Disconnect the option cable if used.
4. Remove the three M3.5-0.6 x 8 TORX screws (#15
drive) securing the board to the frame.
5. Carefully work the board out of the radio, unplugging it
from the feed through assembly Z903.
6. Disconnect the ribbon cable from the rear of the assem-
bly. The Front Cap Assembly can then be removed from
the radio.
TO REMOVE THE HANDSET
INTERFACE BOARD A9
The Front Cap Assembly contains the Handset Inter-
face Board. Remove the Handset Interface Board as in-
structed below.
1. Remove the clip securing the 3 watt PA (U801) to the
front cap casting.
2. Remove the four M3.5-06 x 8 TORX screws (#15 drive)
securing the board to the front cap casting. Lift the board
out of the front cap.
CHIP COMPONENT
REPLACEMENT
The procedure for removing chip components is given
below. Replacement procedures for other unique compo-
nents are located in the related board instruction manual
where the component is used (PA module replacement is
located in the RF Board manual).
Replacement of chip capacitors should always be done
with a temperature controlled soldering iron, operating at
700F (371C). However, DO NOT touch black metal film
of the resistors or the ceramic body of capacitors with the
soldering iron. NOTE: The metallized end terminations of
the parts may be touched with the soldering iron without
causing damage.
To Remove Chip Components
l. Using two soldering irons simultaneously heat each end
of the chip until solder flows, and then remove and
discard the chip.
2. Remove excess solder with a vacuum solder extractor.
3. Carefully remove the epoxy adhesive and excess flux to
prevent damage to the printed board.
To Replace Chip Components
1. Using as little solder as possible, "tin" one end of the
component and one of the pads on the printed wiring
board.
2. Place the "tinned" end of the component on the "tinned"
pad on the board and simultaneously touch the compo-
nent and the pad with a well "tinned" soldering iron while
pressing the component down on the board.
The CMOS Integrated Circuit de-
vices used in this equipment can
be destroyed by static discharges.
Before symbol handling one of
these devices, the serviceman
should discharge himself by
touching the case of a bench in-
strument that has a 3-prong power
cord connected to an outlet with a known good earth
ground. When soldering or desoldering a CMOS
device, the soldering iron should also have a 3-prong
power cord connected to an outlet with a known
good earth ground. A battery-operated soldering
iron may be used in place of the regular soldering
iron.
CAUTION
LBI-38701
7