140 Interface Fault Finding TP9100 Service Manual
© Tait Electronics Limited May 2005
7. If the keypad operates as expected, the loom was faulty. Discard and
use a new one. If still faulty, remove the front panel and replace the
main-shield assembly with a known good assembly.
8. Reassemble and power-up the radio. Check the functionality of the
keypad.
9. If the keypad operates as expected, the main-shield assembly was
faulty. Discard and use a new one. If the keypad is still faulty, the
problem is with the main board.
10. Check for obvious faults around the front-panel interface connector
[
PL2]. If no fault can be found, replace the main board.
Task 2 —
LCD Faulty
Use this procedure for faults with the LCD, such as distorted or missing
pixels on the display or backlighting problems. Before proceeding, make
sure the fault is not an issue with programming. For backlighting faults,
make sure backlighting is enabled in the programming application.
If the LCD is faulty:
1. Remove the front panel.
2. Remove the main-shield assembly, and fold the assembly open leaving
the loom connected between the front panel and the main board.
3. Check the integrity of the front-panel loom and confirm it is seated
correctly at both ends (
RADIO and KEYPAD).
4. Check the integrity of the LCD assembly loom and its connection to
the LCD connector on the main-shield assembly.
5. Reassemble and power-up the radio. Check the functionality of the
LCD.
6. If still faulty, replace the LCD assembly with a known good assembly.
7. Reassemble and power-up the radio. Check the functionality of the
LCD.
8. If the LCD operates as expected, the LCD assembly was faulty.
Discard and use a new one. If still faulty, remove the front panel and
replace the front-panel loom with a known good one.
9. If the LCD operates as expected, the loom was faulty. Discard and use
a new one. If the LCD is still faulty, remove the front panel and
replace the main-shield assembly with a known good assembly.
10. If the LCD operates as expected, the main-shield assembly was faulty.
Discard and use a new one. If the keypad is still faulty, the problem is
with the main board.
11. Check for obvious faults around the front-panel interface connector
[
PL2]. If no fault can be found, replace the main board.
To Next Page
Loading...
