Tait TM8000 Series Service Manual page 153

Task 1 —
Display Faulty but not
LEDs — Check
Elastomeric Strips
Task 2 —
Display Faulty but not
LEDs — Replace LCD
TM8100 Mobile Radio Service Manual
May 2004 © Tait Electronics Limited
If all the LEDs function correctly but the display functions only partially
or not at all, first check the elastomeric strips as follows:
1. Disconnect the control-head loom from the control head.
Remove the control-head board as described in
(on page 131).
2. Remove the elastomeric strips and check the conductors in the
strips for continuity. Replace the strips if they are faulty. (Obtain
spare strips by disassembling the spare control head of Spares kit 1
or 10 as described in
3. Ensure that the conductors along the edges of the strips are clean.
Use isopropyl alcohol and a soft lens-cleaning cloth to clean the
edges.
4. Use isopropyl alcohol and a soft lens-cleaning cloth to clean the
pads for the LCD on the control-head board. See
5. Insert the elastomeric strips in their slots in the space-frame.
6. Install the control-head board as described in
(on page 148).
7. Reconnect the control-head loom to the control head and test the
user interface. If the fault has been removed, return to
Subsection 5.2 (on page
If the elastomeric strips are not the cause of the fault, replace the LCD
as follows:
1. Disconnect the control-head loom. Remove the control-head
board and disassemble the control head as described in
Subsection 6.2.
2. Remove the LCD. Obtain a spare LCD by disassembling the spare
control head of Spares kit 1 or 10 as described in
3. Use isopropyl alcohol and a soft lens-cleaning cloth to clean the
electrical contact points on the spare LCD. Take care not to
scratch the soft polariser material on both sides of the LCD.
4. Re-assemble the control head as described in
5. Reconnect the control-head loom and test the user interface. If
the fault has been removed, return to
go to Step 6.
6. The control-head board is suspect. Level-1 service centres should
replace the board as described in
Level-2 service centres should attempt to repair the board as
described in Subsection 7.2 (on page
Subsection 6.2.)
109). If it has not, go to Task 2.
Subsection
Subsection 7.4 (on page
157).
Servicing of Control Head
Subsection 6.2
Figure 7.1.
Subsection 6.5
Subsection 6.2.
Subsection 6.5.
5.2. If it has not,
163).
153