Technical Manual

IS THE CALL RECEIVED?
CHECK
REALIGN AND
DE-CASE.
PLACE IN P671.
CHECK 1V LINE.
IS LEVEL 1V ±50mV?
CHECK TP416, TR406,
IC401.
SEND PRE-AMBLE.
AT 50dBm WITH
±4.5kHz DEVIATION.
IS DATA PRESENT ON
IC401 PIN 18?
IS DATA PRESENT ON
IC401 PIN 12?
CHECK IC402,
PINS 4, 9, 12, 13 AND 14
CHECK IC401
IS DATA PRESENT ON
IC401 PIN 11?
IS 455kHz PRESENT ON
IC401 PIN 10?
IS VOLTAGE ON
IC401 PIN 17
>1.3V?
CHECK FL404 AND
IC401 FAULTY.
CHECK IC402
AND R457.
CHECK R425, R429
IC401.
IS 455kHz PRESENT ON
IC401 PIN 6?
SENSITIVITY.
RECEIVER
RE-TEST
O.K.
NO
LOW
>3dBm
O.K.
YES
NOYES
YES
NO
YES
NO
YES
NO
YESNO
YES
NO
YES
NO
‘B’
‘C’
PLACE THE UNIT IN THE
P671. SEND A CALL.
TAG11134-1
‘B’
TLA 852/FLA 872
TM1205 Issue 2Page 5 - 12
Figure 5.6: Fault Finding Guide (Sheet 2 of 3)