174
Diagnosis of Faults on Main Board
TM8100 Mobile Radio
Service Manual
May 2004 © Tait Electronics Limited
Task 2 —
Check 3.3 V Supply
If the inputs at pin 5 and pin 7 of IC602 in the SMPS circuitry are
correct, but the radio fails to power up, then the 3.3 V DC supply needs
to be investigated.
1.
First determine as follows if a fault on the digital board is affecting
the supply or preventing the radio from powering up: While
keeping the
ON
/
OFF
key depressed, measure the supply at the
3
V
3
test point [at 1N0/1B11] near the corner of the digital board (see
). The voltage is 3.3 ± 0.1 V when there is no fault. If
the voltage is correct, the digital board is faulty; return to
and replace the complete main-board assembly. If
the voltage is not correct, go to Step 2.
Figure 9.2
Important components of the power-supply circuitry on the top side of the main board
SPARES FOR LINKS LK1 TO LK6
CAN FOR DIGITAL BOARD
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 ...