TM8100 Mobile Radio
Service Manual
Diagnosis of Faults on Main Board
173
May 2004 © Tait Electronics Limited
Task 1 —
Check Inputs to SMPS
The test equipment and radio should be set up as described in
. If not already done, remove the main-
board assembly from the chassis. Connect the control head to the
assembly. Then check the SMPS as follows:
1.
Use a multimeter to check the supply voltage at pin 7 [at
6F7/6E6] of IC602 (see
) in the SMPS circuitry; the
voltage should be 13.8 V DC. If it is, go to Step 5. If it is not, go
to Step 2.
2.
Disconnect the 13.8 V supply at the power connector PL100.
Check for continuity and shorts to ground in the path between
the power connector and pin 7 of IC602 (see
). Locate
and repair the fault.
3.
Reconnect the 13.8 V supply. Confirm the removal of the fault
by measuring the voltage at pin 7 of IC602. If the voltage is
correct, continue with Step 4. If it is not, the repair failed; return
to
and replace the complete main-board assembly.
4.
Press the
ON
/
OFF
key. If the radio powers up, return to
. If it does not, go to Step 5.
5.
Check the digital power-up signal at pin 5 [at 6G6/6E6] of IC602
(see
); the signal is active high, namely, when the voltage
exceeds 2.0 V DC. Measure the voltage at pin 5. If it exceeds
2.0 V, go to Task 2. If it does not, go to Step 6.
6.
Keep the probe of the multimeter on pin 5 of IC602 and press the
ON
/
OFF
key. The voltage should exceed 2.0 V DC while the key is
depressed. If it does, go to Task 2. If it does not, go to Step 7.
7.
Disconnect the 13.8 V supply at the power connector PL100.
Check for continuity and shorts to ground in the path from pin 5
of IC602, via R600 [at 6B4/6D2] and via Q709 [at 7C2/7D2] in
the interface circuitry (see Figure 2.6.1), to pin 9 of the control-
head connector SK100 (
ITF
PSU
ON
OFF
line). Locate and repair the
fault. Go to Step 8.
8.
Reconnect the 13.8 V supply. Press the
ON
/
OFF
key. If the radio
powers up, return to Subsection 2.5.1. If it does not, go to Step 9.
9.
With the probe of the multimeter on pin 5 of IC602 (see
), press the
ON
/
OFF
key again. The voltage should exceed
2.0 V DC while the key is depressed. If it does, go to Task 2. If
it does not, the repair failed; return to
and replace
the complete main-board assembly.
Содержание TM8000 Series
Страница 32: ...32 Introduction TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...
Страница 78: ...78 Circuit Descriptions TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...
Страница 106: ...106 General Information TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...
Страница 124: ...124 Servicing Procedure TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...
Страница 164: ...164 Servicing of Control Head TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...