Tait TM8235, Руководство по обслуживанию

Страница: 139 / 578

TM8100/TM8200 Service Manual Disassembly and Reassembly 139
© Tait Electronics Limited June 2006
Fitting the Main-
Board Assembly to
the Chassis
The circled numbers in this section refer to the items in Figure 5.3 on
page 133 . This figure shows the 40W/50W configuration.
1. With the 40W/50W radio, the L-shaped gap pad
1)
must be replaced
each time the main-board assembly
F
is removed from the chassis
G
:
■
Remove any residue of the old gap pad from the audio-PA area on
the underside of the main board (refer to
Figure 5.6 on page 137 )
and the L-shaped ridge of the chassis (refer to Figure 5.3 on
page 133 ).
■
Peel off the transparent film on one side of the gap pad and evenly
press the gap pad on the L-shaped ridge of the chassis.
■
Peel off the transparent film on other of the gap pad.
2. If the thermal paste on the heat-transfer block or the underside of the
main board has been contaminated, new thermal paste must be
applied:
■
Remove any residue of the old thermal paste from both contact
surfaces.
■
Use Dow Corning 340 silicone heat-sink compound
(IPN 937-00000-55).
Important
Ensure that no bristles from the brush come loose and
remain embedded in the paste. The paste needs to be
completely free of contaminants.
■
Use a stiff brush to apply 0.1cm
3
of thermal paste on the heat-
transfer block (refer to Figure 5.3 on page 133 ).
■
Use a stiff brush to apply 0.01cm
3
of thermal paste on the
audio-PA heat sink of the chassis (refer to Figure 5.3 on page 133 )
3. Place the main-board assembly
F
in position in the chassis
G
.
4. Loosely screw in the two screws
I
through the heat-transfer block by
hand.